Methods, apparatuses, and systems for multi-point, multi-cell single-user based multiple input and multiple output transmissions

ABSTRACT

Methods, systems, and storage media for providing multi-cell, multi-point single user (SU) multiple input and multiple output (MIMO) operations are described. In embodiments, an apparatus may receive and process a first set of one or more independent data streams received in a downlink channel from a first transmission point. The apparatus may receive and process a second set of one or more independent data streams received in a downlink channel from a second transmission point. The apparatus may process control information received from the first transmission point or the second transmission point. The control information may include an indication of a quasi co-location assumption to be used for estimating channel characteristics for reception of the first set of one or more independent data streams or the second set of one or more independent data streams. Other embodiments may be described and/or claimed.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/928,759, filed on Oct. 30, 2015 entitled “METHODS,APPARATUSES, AND SYSTEMS FOR MULTI-POINT, MULTI-CELL SINGLE-USER BASEDMULTIPLE INPUT AND MULTIPLE OUTPUT TRANSMISSIONS,” which claims priorityunder 35 U.S.C. § 119 to U.S. Provisional Application No. 62/119,386,filed on Feb. 23, 2015, and to U.S. Provisional Application No.62/147,972, filed on Apr. 15, 2015. The entire disclosures of each ofwhich are hereby incorporated by reference in their entireties.

FIELD

Implementations of the claimed invention generally relate to the fieldof wireless communications, and in particular, providing downlinkchannels from neighboring transmission points in Long Term Evolution(LTE) wireless communications networks.

BACKGROUND

Current wireless communication standards are based on antennaconfigurations including two transmission antenna elements (referred toas “2Tx antennas”) based in part on current deployment assumptions thattypically rely on 2Tx antennas at an evolved node B (eNB). Many eNBs arelikely to continue to include 2Tx antennas (referred to as “2Tx eNBs”)in the near future due to high costs associated with network deploymentof eNBs with four antennas elements (4Tx) or eight antennas elements(8Tx). As a result, in conventional single-point, single-cell multipleinput and multiple output (MIMO) transmission schemes, a maximum numberof transmission layers that can be simultaneously transmitted to a userequipment (UE) is usually limited to two transmission layers. Thus, inmany cases, a UE is only able to receive two downlink transmissions froma serving eNB regardless of the reception capabilities of the UE.

UEs including four reception antenna elements (referred to as “4Rx UEs”)are being developed and will likely be deployed in the near future.Because most eNBs may still include 2Tx antennas, these 2Tx eNBs may notbe capable of providing full utilization, in terms of the peak data rateenhancements, for the 4Rx UEs.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be readily understood by the following detaileddescription in conjunction with the accompanying drawings. To facilitatethis description, like reference numerals designate like structuralelements. Embodiments are illustrated by way of example and not by wayof limitation in the figures of the accompanying drawings.

FIG. 1 illustrates a broadband wireless access (BWA) network inaccordance with various example embodiments;

FIG. 2 illustrates the components of electronic device circuitry, suchas user equipment (UE) circuitry and/or evolved node B (eNB) circuitry,in accordance with various example embodiments;

FIG. 3 illustrates example components of a UE device, in accordance withvarious example embodiments;

FIG. 4 illustrates a process that may be performed by a UE to determinequasi co-location (QCL) assumptions for multi-cell, multi-point singleuser (SU) multiple input and multiple output (MIMO) transmissions, inaccordance with various embodiments;

FIG. 5 illustrates another process that may be performed by a UE todetermine QCL assumptions for multi-cell, multi-point SU-MIMOtransmissions, in accordance with various embodiments;

FIG. 6 illustrates another process that may be performed by a UE todetermine QCL assumptions for multi-cell, multi-point SU-MIMOtransmissions, in accordance with various embodiments;

FIG. 7 illustrates a process that may be performed by an eNB tofacilitate multi-cell, multi-point SU-MIMO transmissions, in accordancewith various embodiments; and

FIG. 8 illustrates another process that may be performed by an eNB tofacilitate multi-cell, multi-point SU-MIMO transmissions, in accordancewith various embodiments.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings.The same reference numbers may be used in different drawings to identifythe same or similar elements. In the following description, for purposesof explanation and not limitation, specific details are set forth suchas particular structures, architectures, interfaces, techniques, etc.,in order to provide a thorough understanding of the various aspects ofthe claimed invention. However, it will be apparent to those skilled inthe art having the benefit of the present disclosure that the variousaspects of the invention claimed may be practiced in other examples thatdepart from these specific details. In certain instances, descriptionsof well-known devices, circuits, and methods are omitted so as not toobscure the description of the present invention with unnecessarydetail.

Various aspects of the illustrative embodiments will be described usingterms commonly employed by those skilled in the art to convey thesubstance of their work to others skilled in the art. However, it willbe apparent to those skilled in the art that alternate embodiments maybe practiced with only some of the described aspects. For purposes ofexplanation, specific numbers, materials, and configurations are setforth in order to provide a thorough understanding of the illustrativeembodiments. However, it will be apparent to one skilled in the art thatalternate embodiments may be practiced without the specific details. Inother instances, well-known features are omitted or simplified in ordernot to obscure the illustrative embodiments.

Further, various operations will be described as multiple discreteoperations, in turn, in a manner that is most helpful in understandingthe illustrative embodiments; however, the order of description shouldnot be construed as to imply that these operations are necessarily orderdependent. In particular, these operations need not be performed in theorder of presentation.

The phrase “in various embodiments,” “in some embodiments,” and the likeare used repeatedly. The phrase generally does not refer to the sameembodiments; however, it may. The terms “comprising,” “having,” and“including” are synonymous, unless the context dictates otherwise. Thephrase “A and/or B” means (A), (B), or (A and B). The phrases “A/B” and“A or B” mean (A), (B), or (A and B), similar to the phrase “A and/orB.” For the purposes of the present disclosure, the phrase “at least oneof A and B” means (A), (B), or (A and B). The description may use thephrases “in an embodiment,” “in embodiments,” “in some embodiments,”and/or “in various embodiments,” which may each refer to one or more ofthe same or different embodiments. Furthermore, the terms “comprising,”“including,” “having,” and the like, as used with respect to embodimentsof the present disclosure, are synonymous.

Example embodiments may be described as a process depicted as aflowchart, a flow diagram, a data flow diagram, a structure diagram, ora block diagram. Although a flowchart may describe the operations as asequential process, many of the operations may be performed in parallel,concurrently, or simultaneously. In addition, the order of theoperations may be re-arranged. A process may be terminated when itsoperations are completed, but may also have additional steps notincluded in the figure(s). A process may correspond to a method, afunction, a procedure, a subroutine, a subprogram, and the like. When aprocess corresponds to a function, its termination may correspond to areturn of the function to the calling function and/or the main function.

As used herein, the term “circuitry” refers to, is part of, or includeshardware components such as an Application Specific Integrated Circuit(ASIC), an electronic circuit, a logic circuit, a processor (shared,dedicated, or group) and/or memory (shared, dedicated, or group) thatare configured to provide the described functionality. In someembodiments, the circuitry may execute one or more software or firmwareprograms to provide at least some of the described functionality.Example embodiments may be described in the general context ofcomputer-executable instructions, such as program code, softwaremodules, and/or functional processes, being executed by one or more ofthe aforementioned circuitry. The program code, software modules, and/orfunctional processes may include routines, programs, objects,components, data structures, etc., that perform particular tasks orimplement particular data types. The program code, software modules,and/or functional processes discussed herein may be implemented usingexisting hardware in existing communication networks. For example,program code, software modules, and/or functional processes discussedherein may be implemented using existing hardware at existing networkelements or control nodes.

As used herein, the term “user equipment” may be considered synonymousto, and may hereafter be occasionally referred to, as a client, mobile,mobile device, mobile terminal, user terminal, mobile unit, mobilestation, mobile user, UE, subscriber, user, remote station, accessagent, user agent, receiver, etc., and may describe a remote user ofnetwork resources in a communications network. Furthermore, the term“user equipment” may include any type of wireless/wired device such asconsumer electronics devices, cellular phones, smartphones, tabletpersonal computers, wearable computing devices, personal digitalassistants (PDAs), desktop computers, and laptop computers, for example.

As used herein, the term “network element” may be considered synonymousto and/or referred to as a networked computer, networking hardware,network equipment, router, switch, hub, bridge, radio networkcontroller, radio access network device, gateway, server, and/or anyother like device. The term “network element” may describe a physicalcomputing device of a wired or wireless communication network and beconfigured to host a virtual machine. Furthermore, the term “networkelement” may describe equipment that provides radio baseband functionsfor data and/or voice connectivity between a network and one or moreusers. The term “network element” may be considered synonymous to and/orreferred to as a “base station.” As used herein, the term “base station”may be considered synonymous to and/or referred to as a node B, anenhanced or evolved node B (eNB), base transceiver station (BTS), accesspoint (AP), etc., and may describe equipment that provides the radiobaseband functions for data and/or voice connectivity between a networkand one or more users.

It should also be noted that the term “channel” as used herein may referto any transmission medium, either tangible or intangible, which is usedto communicate data or a data stream. Additionally, the term “channel”may be synonymous with and/or equivalent to “communications channel,”“data communications channel,” “transmission channel,” “datatransmission channel,” “access channel,” “data access channel,” “link,”“data link,” “carrier,” “radiofrequency carrier,” and/or any other liketerm denoting a pathway or medium through which data is communicated.

Embodiments herein relate to facilitating multi-cell, multi-point singleuser (SU) multiple input and multiple output (MIMO) transmissionswherein multiple transmission layers are provided to a UE by aneighboring or non-serving cell or transmission point. The exampleembodiments provide the following advantages: a multi-cell, multi-pointSU MIMO transmission scheme may improve throughput or data rates indense deployment areas, such as an indoor environment or an relativelylarge urban environment; a multi-cell, multi-point SU MIMO transmissionscheme may provide load balancing by allocating additional transmissionresources to UEs from less loaded or under loaded transmission points;and currently deployed base stations (for example, eNBs) may not requireupgrades to include additional transmission antenna elements, therebysaving network operator costs.

FIG. 1 illustrates an example of a broadband wireless access (BWA)network 100, according to an example embodiment. BWA network 100includes two UEs 105, three eNBs 110 (eNB 110-1, eNB 110-2, and eNB110-3 are collectively referred to as “eNB 110”), and three cells 115(cell 115-1, cell 115-2, and cell 115-3 are collectively referred to as“cell 115”). The following description is provided for an example BWAnetwork 100 that operates in conjunction with the Long Term Evolution(LTE) standard as provided by 3rd Generation Partnership Project (3GPP)technical specifications. However, the example embodiments are notlimited in this regard and the described embodiments may apply to othernetworks that benefit from the principles described herein.

Referring to FIG. 1, each of the UEs 105 (collectively referred to as“UE 105”) may be physical hardware devices capable of running one ormore applications and capable of accessing network services via a radiolink (“link”) with an eNB 110. UE 105 may include a transmitter/receiver(or alternatively, a transceiver), memory, one or more processors,and/or other like components. According to various embodiments, UE 105may include four reception antenna elements (referred to as a “4Rx UE105”). UE 105 may be configured to send/receive data to/from the eNB 110via the link. UE 105 may be designed to sequentially and automaticallycarry out a sequence of arithmetic or logical operations; equipped torecord/store digital data on a machine readable medium; and transmit andreceive digital data via eNB 110. The wireless transmitter/receiver (oralternatively, a transceiver) included in the UE 105 may be configuredto operate in accordance with one or more wireless communicationsprotocols and/or one or more cellular phone communications protocols,such as 3GPP LTE, 3GPP LTE-Advanced (LTE-A), and/or any other wirelesscommunication protocols, including radio frequency (RF)-based, optical(visible/invisible), and so forth. In various embodiments, UE 105 mayinclude wireless phones or smartphones, laptop personal computers (PCs),tablet PCs, wearable computing devices, autonomous sensors or other likemachine type communication (MTC) devices, and/or any other physical orlogical device capable of recording, storing, and/or transferringdigital data to/from eNB 110 and/or any other like network element.

The eNB 110 is a hardware computing device configured to providewireless communication services to mobile devices (for example, UEs 105)within a geographic area or cell 115 associated with an eNB 110 (forexample, cell 115-1 associated with eNB 110-1). The cell 115 may also bereferred to as a “serving cell,” “cell coverage area,” and the like. TheeNB 110 may provide wireless communication services to UE 105 via one ormore links 120 for each UE 105. As shown by FIG. 1, links 120 betweeneNB 110 and a UE 105 may include one or more downlink (or forward)channels for transmitting information from eNB 110 to UE 105. Althoughnot shown by FIG. 1, links 120 may also include one or more uplink (orreverse) channels for transmitting information from UE 105 to the eNB110. The channels may include the physical downlink shared channel(PDSCH), physical downlink control channel (PDCCH), physical hybridautomatic repeat request (HARQ) indicator channel (PHICH), physicalcontrol format indicator channel (PCFICH), physical broadcast channel(PBCH), physical uplink shared channel (PUSCH), physical uplink controlchannel (PUCCH), physical random access channel (PRACH), and/or anyother like communications channels or links used to transmit/receivedata.

In various embodiments, eNBs 110 include a transmitter/receiver (oralternatively, a transceiver) connected to one or more antennas, one ormore memory devices, one or more processors, and/or other likecomponents. The one or more transmitters/receivers may be configured totransmit/receive data signals to/from one or more UEs 105 within itscell 115 via one or more links that may be associated with a transmitterand a receiver. The eNB 110 or a transmitter of an eNB 110 may bereferred to as a “transmission point.” In various embodiments, when BWAnetwork 100 employs the LTE or LTE-A standard, eNBs 110 may employEvolved Universal Terrestrial Radio Access (E-UTRA) protocols, forexample, using orthogonal frequency-division multiple access (OFDMA) fordownlink communications and single carrier frequency-division multipleaccess (SC-FDMA) for uplink communications.

In many deployment scenarios, such as BWA network 100, one or more ofthe eNBs 110 may only include two transmission antenna elements(referred to as a “2Tx eNB”) due in part to the prohibitive costsassociated with upgrading the eNBs 110 to include more than twotransmission antennas. In conventional systems, each eNB 110 may only becapable of providing single-point, single-cell MIMO coverage for a UE105, wherein only one serving cell 115 is able to provide downlinktransmissions to a UE 105 (for example, eNB 110-3 serving a single UE105 as shown by FIG. 1). According to various example embodiments, a UE105 may receive transmission layers, not only from a serving cell 115,but also from one or more neighboring cells 115 that have availabledownlink resources. For example, as shown in FIG. 1, a serving 2Tx eNB110-1 may transmit two transmission layers and a neighboring 2Tx eNB110-2 having available downlink resources may also provide twotransmission layers, such that a total transmit of four transmissionlayers are received by a 4Rx UE 105. By performing such transmissions, aUE 105 may boost a peak data rate by decoding up to four transmissionlayers at the same or similar time, where some of the layers aretransmitted by a first service cell, for example, service cell 115-1,and other layers are transmitted by neighboring cells, for example,service cell 115-2. To spatially separate the multiple layers on thesame frequency, the 4Rx UE 105 may use four reception antenna elementswith a receiver capable of suppressing the interference from theinterfering layers. Such receivers may be minimum mean square errorinterference rejection combining (MMSE-IRC) receivers, reducedcomplexity maximum likelihood (R-ML) receivers, symbol levelinterference cancellation (SLIC) or code-word interference cancellation(CWIC) receivers, and/or other like receivers. Furthermore, in somedeployment scenarios, the number of layers from a single eNB 110 may belimited by propagation characteristics of a channel, for example, aline-of-sight, which may limit the number of MIMO layers to betransmitted to two MIMO layers. For example, in the BWA network 100, aserving eNB 110-1, which has more than two antenna elements, may only beable to transmit two transmission layers due to various propagationcharacteristics, and a neighboring eNB 110-2 having available downlinkresources may also provide two transmission layers, such that a totaltransmit of four transmission layers are received by a 4Rx UE 105.

In other embodiments, the number of transmitted layers may be differenton different transmission points or cells 115. For example, the eNB110-1 may transmit two (spatial) transmission layers and the eNB 110-2may transmit one transmission layer (not shown). In another example, theeNB 110-1 may transmit two spatial transmission layers, the eNB 110-2may transmit one transmission layer, and the eNB 110-3 may transmit onetransmission layer when the UE 105 is located in an area where all threeof the cells 115 converge (not shown). Furthermore, although FIG. 1shows three eNBs 110, the example embodiments provide that a neighboringcell may be provided by a small cell, such as a femtocell, picocell, orany other suitable network element. The aforementioned transmissionschemes may be referred to as multi-cell, multi-point SU-MIMOtransmission schemes.

Multi-point transmissions may refer to transmissions being carried outby multiple transmission points or cells 115. When multipletransmissions points coordinate with one another to provide multi-pointtransmissions, these transmission points are considered to be a part ofa collaborative multipoint (CoMP) transmission scheme. Current CoMPtransmission schemes include dynamic point selection and jointtransmission. Dynamic point selection includes transmitting from asingle transmission point, where the transmission point may be changeddynamically. Joint transmission (also referred to as “joint processing”and “cooperative MIMO”) includes simultaneous transmissions frommultiple transmission points, wherein each transmission point transmitson the same frequency in the same subframe based on relatively extensivebackhaul communications between the transmission points. For most CoMPtransmission schemes, it is typically assumed that a UE 105 receives allMIMO layers using quasi co-located UE-specific RS antenna ports, whichimplies that the precoding is performed jointly by all transmissionpoints.

Antenna ports are logical entities distinguished by reference signalsequences. Multiple antenna port signals can be transmitted on a singlephysical transmit antenna element, and/or a single antenna port can bespread across multiple physical transmit antenna elements. Antenna ports0-3 are indicated by or otherwise associated with cell-specificreference signals (CRSs), antenna ports 5 and 7-14 are indicated by orotherwise associated with UE-specific reference signals (UE-specificRSs) (also referred to as a demodulation reference signals (DMRSs)), andantenna ports 15-22 are indicated by or otherwise associated withchannel state information reference signals (CSI-RSs). Currentspecifications delineate that UE-specific antenna ports used to transmitspatial layers are assumed to be quasi co-located with one another.

The term “quasi co-located” means that two or more antenna ports aresaid to be quasi co-located if large-scale properties of a channel overwhich a symbol on one antenna port is conveyed can be inferred from achannel over which a symbol on another antenna port is conveyed. Thelarge-scale channel properties include one or more of delay spread,Doppler spread, Doppler shift, average gain, average delay, receptiontiming, and the like. When two antenna ports are quasi co-located, a UE105 may assume that large-scale channel properties of a signal receivedfrom a first antenna port can be inferred from a signal received from asecond antenna port. For example, when a UE 105 is to decode a receivedPDSCH transmission, the UE 105 may perform a channel estimationoperation using an associated UE-specific RS. In order to perform thechannel estimation operation, the UE 105 may need to know thelarge-scale channel properties for that channel. Using the quasico-location (QCL) assumptions of the current standards, a UE 105 that isconfigured for transmission modes 1-9 may assume that, for a servingcell, CRS antenna ports, CSI-RS antenna ports, and UE-specific RSantenna ports are quasi co-located.

A UE 105 configured for transmission mode 10 may operate according totwo QCL types, for example, type A and type B. When the UE 105 isconfigured as a type A UE, the UE 105 may assume that the CRS,UE-specific RS, and CSI-RS antenna ports are quasi co-located, which isthe QCL assumption for transmission modes 1-9. When the UE 105 isconfigured as a type B UE, the UE 105 may assume the CSI-RS antennaports corresponding to a CSI-RS resource configuration identified byhigher-layer signaling (for example, a radio resource control (RRC)signaling) and the UE-specific RS antenna ports associated with thePDSCH are quasi co-located. For the UE 105 configured for transmissionmode 10, the QCL type may be signaled to the UE 105 by higher-layersignaling (for example, RRC signaling). The QCL assumption of thecurrent standards implies that all transmission layers are transmittedfrom the same transmission point, which means that only single-point,single-cell SU-MIMO is currently supported by the current standards.

In order to provide multi-cell, multi-point SU-MIMO, example embodimentsprovide that the current QCL assumptions for UE-specific RS are adjusted(or removed) in order to accommodate channel characteristics fordifferent transmission layers being transmitted from differenttransmission points. In some embodiments, the QCL assumptions areadjusted only for UEs configured for transmission mode 10. Exampleembodiments provide for QCL assumption adjustments because channelsassociated with different transmission points may have different channelcharacteristics, and thus, time and frequency synchronization errors mayoccur if the UE 105 infers the channel properties derived from antennaports used for transmissions from a first transmission point for antennaports used for transmissions from a second transmission point.

Although not shown by FIG. 1, each eNB 110 may be part of a radio accessnetwork (RAN) or associated with a radio access technology (RAT). Inembodiments where communications network 100 employs the LTE standard,the RAN may be referred to as an evolved universal terrestrial radioaccess network (E-UTRAN). RANs and their typical functionality aregenerally well-known, and thus, a further detailed description of thetypical functionality of RAN is omitted. Furthermore, although not shownby FIG. 1, the BWA network 100 may include a core network (CN), whichmay include one or more hardware devices, such as the one or moreservers. These servers may provide various telecommunications servicesto the UEs 105. In embodiments where BWA network 100 employs the LTEstandards, the one or more servers of the CN may comprise components ofthe System Architecture Evolution (SAE) with an Evolved Packet Core(EPC) as described by 3GPP technical specifications. In suchembodiments, the one or more servers of the CN may include componentssuch as a node including a mobility management entity (MME) and/or aserving General Packet Radio Service Support Node (SGSN) (which may bereferred to as an “SGSN/MME”), serving gateway (SGW), packet datanetwork (PDN) gateway (PGW), home subscriber server (HSS), accessnetwork discovery and selection function (ANDSF), evolved packet datagateway (ePDG), an MTC interworking function (IWF), and/or other likecomponents as are known. Because the components of the SAE core networkand their functionality are generally well-known, a further detaileddescription of the SAE core network is omitted. It should also be notedthat the aforementioned functions may be provided by the same physicalhardware device or by separate components and/or devices.

Although FIG. 1 shows three cell coverage areas (for example, cells115), three base stations (for example, eNBs 110), and two mobiledevices (for example, UEs 105), it should be noted that in variousexample embodiments, BWA network 100 may include many more eNBs servingmany more UEs than those shown in FIG. 1. However, it is not necessarythat all of these generally conventional components be shown in order tounderstand the example embodiments as described herein.

FIG. 2 illustrates the components of electronic device circuitry 200,which may be eNB circuitry, UE circuitry, or some other type ofcircuitry, in accordance with various embodiments. In embodiments, theelectronic device circuitry may be, or may be incorporated into orotherwise a part of, a UE 105, an eNB 110, or some other type ofelectronic device. As shown, the electronic device circuitry 200includes control circuitry 205, transmit circuitry 210, and receivecircuitry 215.

According to various embodiments, the transmit circuitry 210 and thereceive circuitry 215 may be coupled with one or more antennas tofacilitate over-the-air transmissions with, for example, the eNB 110.For example, the transmit circuitry 210 may be configured to receivedigital data from one or more components of eNB 110, and convert thereceived digital data into an analog signal for transmission over an airinterface by way of the one or more antennas. The receive circuitry 215may be any type of hardware device that can receive and convert a signalfrom a modulated radio wave into usable information, such as digitaldata. Receive circuitry 215 may be coupled with the one or more antennasin order to capture the radio waves. Receive circuitry 215 may beconfigured to send digital data converted from a captured radio wave toone or more other components of the UE 105. It should be noted that thetransmit circuitry 210 and the receive circuitry 215 may be collectivelyreferred to as “signal circuitry,” “signaling circuitry,” and the like.In embodiments, the transmit circuitry 210 and the receive circuitry 215may be coupled to the control circuitry 205. In some embodiments wherethe electronic device circuitry 200 is a UE 105 or otherwise a part of aUE 105, the receive circuitry 215 may be a receiver or a part of areceiver, such as an MMSE-IRC receiver, an R-ML receiver, an SLIC or aCWIC receiver, and/or any other like suitable receiver. The controlcircuitry 205 may be configured to perform control operations describedherein with respect to the UE 105 and/or the eNB 110. The components ofthe UE 105 circuitry may be configured to perform operations similar tothose described elsewhere in the present disclosure with respect to a UE105.

In embodiments where the electronic device circuitry 200 is a UE 105 oris incorporated into or otherwise part of a UE 105, the antenna arraymay include at least a first receive antenna and a second receiveantenna. For example, the one or more antennas may be an antenna arraythat includes a first receive antenna, a second receive antenna, a thirdreceive antenna, and a fourth receive antenna. The receive circuitry 215may be configured to receive a first set of one or more independent datastreams in a downlink channel of a first cell, for example, cell 115-1.The receive circuitry 215 may be further configured to receive a secondset of one or more independent data streams in a downlink channel of asecond cell, such as cell 115-2. The receive circuitry 215 may befurther configured to receive, from the first cell and/or the secondcell, control information that includes an indication of a parameter ofthe first or second set of one or more independent data streams. Theindication may indicate a QCL assumption to be used for determiningchannel characteristics for reception of the independent data streams.Furthermore, the control circuitry 205 may be configured to perform theprocesses described herein, such as processes 400-600 described withrespect to FIGS. 4-6.

In embodiments where the electronic device circuitry 200 is atransmission point and/or downlink cell, or is incorporated into orotherwise part of a transmission point and/or downlink cell (forexample, eNB 110-1 associated with cell 115-1) the control circuitry 205may be configured to identify control information related to a parameterof a first independent data stream that is to be transmitted by thedownlink cell or a second independent data stream that is to betransmitted by another downlink cell (for example, eNB 110-2 associatedwith cell 115-2). In such embodiments, the transmit circuitry 210 may beconfigured to transmit the first independent data stream and the controlinformation to a UE 105. The parameter may indicate a QCL assumption tobe used to determine channel characteristics for reception of the firstindependent data stream and/or the second independent data stream. Theindication may indicate a QCL assumption to be used for determiningchannel characteristics for reception of the independent data streams.Furthermore, the control circuitry 205 may be configured to perform theprocesses described herein, such as processes 700-800 described withrespect to FIGS. 7-8.

FIG. 3 illustrates, for one embodiment, example components of anelectronic device 300. In various embodiments, the electronic device 300may be the same or similar to UE 105 as described previously with regardto FIGS. 1-2. In some embodiments, the electronic device 300 may includeapplication circuitry 302, baseband circuitry 304, radio frequency (RF)circuitry 306, front-end module (FEM) circuitry 308 and one or moreantennas 310, coupled together at least as shown.

The application circuitry 302 may include one or more applicationprocessors. For example, the application circuitry 302 may includecircuitry such as, but not limited to, one or more single-core ormulti-core processors. The processor(s) may include any combination ofgeneral-purpose processors and dedicated processors (e.g., graphicsprocessors, application processors, etc.). The processors may be coupledwith and/or may include memory/storage and may be configured to executeinstructions stored in the memory/storage to enable various applicationsand/or operating systems to run on the system.

The baseband circuitry 304 may include circuitry such as, but notlimited to, one or more single-core or multi-core processors. Thebaseband circuitry 304 may include one or more baseband processorsand/or control logic to process baseband signals received from a receivesignal path of the RF circuitry 306 and to generate baseband signals fora transmit signal path of the RF circuitry 306. Baseband circuitry 304may interface with the application circuitry 302 for generation andprocessing of the baseband signals and for controlling operations of theRF circuitry 306. For example, in some embodiments, the basebandcircuitry 304 may include a second generation (2G) baseband processor304 a, third generation (3G) baseband processor 304 b, fourth generation(4G) baseband processor 304 c, and/or other baseband processor(s) 304 dfor other existing generations, generations in development or to bedeveloped in the future (e.g., fifth generation (5G), 6G, etc.). Thebaseband circuitry 304 (e.g., one or more of baseband processors 304a-d) may handle various radio control functions that enablecommunication with one or more radio networks via the RF circuitry 306.The radio control functions may include, but are not limited to, signalmodulation/demodulation, encoding/decoding, radio frequency shifting,and the like. In some embodiments, modulation/demodulation circuitry ofthe baseband circuitry 304 may include Fast-Fourier Transform (FFT),precoding, and/or constellation mapping/demapping functionality. In someembodiments, encoding/decoding circuitry of the baseband circuitry 304may include convolution, tail-biting convolution, turbo, Viterbi, and/orLow Density Parity Check (LDPC) encoder/decoder functionality.Embodiments of modulation/demodulation and encoder/decoder functionalityare not limited to these examples and may include other suitablefunctionality in other embodiments.

In some embodiments, the baseband circuitry 304 may include elements ofa protocol stack such as, for example, elements of an evolved universalterrestrial radio access network (E-UTRAN) protocol including, forexample, physical (PHY), media access control (MAC), radio link control(RLC), packet data convergence protocol (PDCP), and/or radio resourcecontrol (RRC) elements. A central processing unit (CPU) 304 e of thebaseband circuitry 304 may be configured to run elements of the protocolstack for signaling of the PHY, MAC, RLC, PDCP and/or RRC layers. Insome embodiments, the baseband circuitry may include one or more audiodigital signal processor(s) (DSP) 304 f. The audio DSP(s) 304 f mayinclude elements for compression/decompression and echo cancellation andmay include other suitable processing elements in other embodiments.Components of the baseband circuitry 304 may be suitably combined in asingle chip, a single chipset, or disposed on a same circuit board insome embodiments. In some embodiments, some or all of the constituentcomponents of the baseband circuitry 304 and the application circuitry302 may be implemented together, such as, for example, on a system on achip (SOC).

In some embodiments, the baseband circuitry 304 may provide forcommunication compatible with one or more radio technologies. Forexample, in some embodiments, the baseband circuitry 304 may supportcommunication with an E-UTRAN and/or other wireless metropolitan areanetworks (WMAN), a wireless local area network (WLAN), a wirelesspersonal area network (WPAN). Embodiments in which the basebandcircuitry 304 is configured to support radio communications of more thanone wireless protocol may be referred to as multi-mode basebandcircuitry.

RF circuitry 306 may enable communication with wireless networks usingmodulated electromagnetic radiation through a non-solid medium. Invarious embodiments, the RF circuitry 306 may include switches, filters,amplifiers, etc., to facilitate the communication with the wirelessnetwork. RF circuitry 306 may include a receive signal path that mayinclude circuitry to down-convert RF signals received from the FEMcircuitry 308 and provide baseband signals to the baseband circuitry304. RF circuitry 306 may also include a transmit signal path that mayinclude circuitry to up-convert baseband signals provided by thebaseband circuitry 304 and provide RF output signals to the FEMcircuitry 308 for transmission.

In some embodiments, the RF circuitry 306 may include a receive signalpath and a transmit signal path. The receive signal path of the RFcircuitry 306 may include mixer circuitry 306 a, amplifier circuitry 306b and filter circuitry 306 c. The transmit signal path of the RFcircuitry 306 may include filter circuitry 306 c and mixer circuitry 306a. RF circuitry 306 may also include synthesizer circuitry 306 d forsynthesizing a frequency for use by the mixer circuitry 306 a of thereceive signal path and the transmit signal path. In some embodiments,the mixer circuitry 306 a of the receive signal path may be configuredto down-convert RF signals received from the FEM circuitry 308 based onthe synthesized frequency provided by synthesizer circuitry 306 d. Theamplifier circuitry 306 b may be configured to amplify thedown-converted signals and the filter circuitry 306 c may be a low-passfilter (LPF) or band-pass filter (BPF) configured to remove unwantedsignals from the down-converted signals to generate output basebandsignals. Output baseband signals may be provided to the basebandcircuitry 304 for further processing. In some embodiments, the outputbaseband signals may be zero-frequency baseband signals, although thisis not a requirement. In some embodiments, mixer circuitry 306 a of thereceive signal path may comprise passive mixers, although the scope ofthe embodiments is not limited in this respect.

In some embodiments, the mixer circuitry 306 a of the transmit signalpath may be configured to up-convert input baseband signals based on thesynthesized frequency provided by the synthesizer circuitry 306 d togenerate RF output signals for the FEM circuitry 308. The basebandsignals may be provided by the baseband circuitry 304 and may befiltered by filter circuitry 306 c. The filter circuitry 306 c mayinclude a low-pass filter (LPF), although the scope of the embodimentsis not limited in this respect.

In some embodiments, the mixer circuitry 306 a of the receive signalpath and the mixer circuitry 306 a of the transmit signal path mayinclude two or more mixers and may be arranged for quadraturedownconversion and/or upconversion, respectively. In some embodiments,the mixer circuitry 306 a of the receive signal path and the mixercircuitry 306 a of the transmit signal path may include two or moremixers and may be arranged for image rejection (e.g., Hartley imagerejection). In some embodiments, the mixer circuitry 306 a of thereceive signal path and the mixer circuitry 306 a of the transmit signalpath may be arranged for direct downconversion and/or directupconversion, respectively. In some embodiments, the mixer circuitry 306a of the receive signal path and the mixer circuitry 306 a of thetransmit signal path may be configured for super-heterodyne operation.

In some embodiments, the output baseband signals and the input basebandsignals may be analog baseband signals, although the scope of theembodiments is not limited in this respect. In some alternateembodiments, the output baseband signals and the input baseband signalsmay be digital baseband signals. In these alternate embodiments, the RFcircuitry 306 may include analog-to-digital converter (ADC) anddigital-to-analog converter (DAC) circuitry and the baseband circuitry304 may include a digital baseband interface to communicate with the RFcircuitry 306.

In some dual-mode embodiments, a separate radio IC circuitry may beprovided for processing signals for each spectrum, although the scope ofthe embodiments is not limited in this respect.

In some embodiments, the synthesizer circuitry 306 d may be afractional-N synthesizer or a fractional N/N+1 synthesizer, although thescope of the embodiments is not limited in this respect, as other typesof frequency synthesizers may be suitable. For example, synthesizercircuitry 306 d may be a delta-sigma synthesizer, a frequencymultiplier, or a synthesizer comprising a phase-locked loop with afrequency divider. The synthesizer circuitry 306 d may be configured tosynthesize an output frequency for use by the mixer circuitry 306 a ofthe RF circuitry 306 based on a frequency input and a divider controlinput. In some embodiments, the synthesizer circuitry 306 d may be afractional N/N+1 synthesizer.

In some embodiments, frequency input may be provided by a voltagecontrolled oscillator (VCO), although that is not a requirement. Dividercontrol input may be provided by either the baseband circuitry 304 orthe application circuitry 302 depending on the desired output frequency.In some embodiments, a divider control input (e.g., N) may be determinedfrom a look-up table based on a channel indicated by the applicationcircuitry 302.

Synthesizer circuitry 306 d of the RF circuitry 306 may include adivider, a delay-locked loop (DLL), a multiplexer and a phaseaccumulator. In some embodiments, the divider may be a dual modulusdivider (DMD) and the phase accumulator may be a digital phaseaccumulator (DPA). In some embodiments, the DMD may be configured todivide the input signal by either N or N+1 (e.g., based on a carry out)to provide a fractional division ratio. In some example embodiments, theDLL may include a set of cascaded, tunable, delay elements, a phasedetector, a charge pump and a D-type flip-flop. In these embodiments,the delay elements may be configured to break a VCO period up into Ndequal packets of phase, where Nd is the number of delay elements in thedelay line. In this way, the DLL provides negative feedback to helpensure that the total delay through the delay line is one VCO cycle.

In some embodiments, synthesizer circuitry 306 d may be configured togenerate a carrier frequency as the output frequency, while in otherembodiments, the output frequency may be a multiple of the carrierfrequency (e.g., twice the carrier frequency, four times the carrierfrequency) and used in conjunction with quadrature generator and dividercircuitry to generate multiple signals at the carrier frequency withmultiple different phases with respect to each other. In someembodiments, the output frequency may be a LO frequency (fLo). In someembodiments, the RF circuitry 306 may include an IQ/polar converter.

FEM circuitry 308 may include a receive signal path that may includecircuitry configured to operate on RF signals received from one or moreantennas 310, amplify the received signals and provide the amplifiedversions of the received signals to the RF circuitry 306 for furtherprocessing. FEM circuitry 308 may also include a transmit signal paththat may include circuitry configured to amplify signals fortransmission provided by the RF circuitry 306 for transmission by one ormore of the one or more antennas 310. In some embodiments, the FEMcircuitry 308 may include a TX/RX switch to switch between transmit modeand receive mode operation. The FEM circuitry 308 may include a receivesignal path and a transmit signal path. The receive signal path of theFEM circuitry may include a low-noise amplifier (LNA) to amplifyreceived RF signals and provide the amplified received RF signals as anoutput (e.g., to the RF circuitry 306). The transmit signal path of theFEM circuitry 308 may include a power amplifier (PA) to amplify input RFsignals (e.g., provided by RF circuitry 306), and one or more filters togenerate RF signals for subsequent transmission (e.g., by one or more ofthe one or more antennas 310).

In some embodiments, the electronic device 300 may include additionalelements such as, for example, memory/storage, display, camera, sensor,and/or input/output (I/O) interface (not shown).

In some embodiments, the RF circuitry 306 may be a receiver, orotherwise included in a receiver, such as an MMSE-IRC receiver, an R-MLreceiver, an SLIC or CWIC receiver, and/or any other suitable receiver.

In embodiments where the electronic device 300 is a UE 105 or isincorporated into or otherwise part of a UE 105, the one or moreantennas 310 may include at least a first receive antenna and a secondreceive antenna. For example, the one or more antennas 310 may be anantenna array that includes a first receive antenna, a second receiveantenna, a third receive antenna, and a fourth receive antenna. The RFcircuitry 306 may be configured to receive a first set of one or moreindependent data streams in a downlink channel of a first downlink cell,for example, cell 115-1. The RF circuitry 306 may be further configuredto receive a second set of one or more independent data streams in adownlink channel of a second downlink cell, such as cell 115-2. The RFcircuitry 306 may be further configured to receive, from the firstand/or second downlink cells, control information that includes anindication of a parameter of the first or second set of one or moreindependent data streams. The indication (or parameter) may indicate aQCL assumption to be used for determining channel characteristics forreception of the independent data streams. Furthermore, the basebandcircuitry 304 may be configured to perform the processes describedherein, such as processes 400-600 described with respect to FIGS. 4-6.

In embodiments where the electronic device 300 is a transmission pointand/or downlink cell, or is incorporated into or otherwise part of atransmission point and/or downlink cell (for example, eNB 110-1associated with cell 115-1), the baseband circuitry 304 may beconfigured to identify control information related to a parameter of afirst independent data stream that is to be transmitted by the downlinkcell or a second independent data stream that is to be transmitted byanother downlink cell (for example, eNB 110-2 associated with cell115-2). In such embodiments, the RF circuitry 306 may be configured totransmit the first independent data stream and the control informationto a UE 105. The indication (or parameter) may indicate a QCL assumptionto be used for determining channel characteristics for reception of theindependent data streams. Furthermore, the baseband circuitry 304 may beconfigured to perform the processes described herein, such as processes700-800 described with respect to FIGS. 7-8.

FIG. 4 illustrates a process 400 that may be performed by a UE 105 todetermine QCL assumptions for multi-cell, multi-point SU-MIMOtransmissions, in accordance with various embodiments. In someembodiments, the UE 105 may include one or more non-transitorycomputer-readable media having instructions, stored thereon, which whenexecuted by the UE 105, cause the UE 105 to perform the process 400. Forillustrative purposes, the operations of process 400 will be describedas being performed by the UE 105, which is described with respect toFIGS. 1-3. However, it should be noted that other similar devices mayoperate the process 400. While particular examples and orders ofoperations are illustrated in FIG. 4, in various embodiments, theseoperations may be re-ordered, broken into additional operations,combined, and/or omitted altogether. In some embodiments, the operationsillustrated in FIG. 4 may be combined with operations described withregard to other embodiments, such as those illustrated by one or more ofFIGS. 5-8 and/or one or more operations described with regard to thenon-limiting examples provided herein.

Referring to FIG. 4, at operation 405 the UE 105 may process a first setof one or more independent data streams received in a downlink channelfrom a first transmission point. At operation 410, the UE 105 mayprocess a second set of one or more independent data streams received ina downlink channel from a second transmission point. Each independentdata stream may correspond with a transmission layer (also referred toas a “layer” herein). In some embodiments, at least one independent datastream may be transmitted by at least one antenna port of a plurality ofantenna ports associated with one or more reference signals, such asUE-specific RSs of the first transmission point or the secondtransmission point.

At operation 415, the UE 105 may process control information receivedfrom either the first transmission point or the second transmissionpoint. At operation 420, the UE 105 may determine a QCL assumption to beused for estimating channel characteristics for reception of the firstset of one or more independent data streams or for reception of thesecond set of one or more independent data streams. The controlinformation may include an indication of a QCL assumption to be used forestimating channel characteristics for reception of the first set of oneor more independent data streams or for reception of the second set ofone or more independent data streams. According to various embodiments,the UE 105 may not assume that the plurality of antenna ports are quasico-located with respect to at least one of a Doppler shift, a Dopplerspread, an average delay, or delay spread. In some embodiments, theindication may indicate that no QCL assumption is to be used, while inother embodiments, the indication may indicate an appropriate QCLassumption to be used. At operation 425, the UE 105 may estimate channelcharacteristics for reception of the first set of one or moreindependent data streams or for reception of the second set of one ormore independent data streams according to the quasi co-locationassumption.

When the indication indicates that no QCL assumption is to be used, andthe UE 105 may assume the same channel characteristics (for example, asame Doppler shift, Doppler spread, average delay, and delay spread)over a predefined set of physical resource blocks (PRBs). In suchembodiments, the UE 105 may perform channel estimation for downlinkchannels from each transmission point separately over the predefined setof PRBs. The predefined set of PRBs may be a PRB bundling set. A PRBbundling set may include two or more PRB bundles. Each PRB bundle mayinclude a number of contiguous or consecutive PRBs that are scheduledfor the UE 105. The UE 105 may assume that the consecutive PRBs in a PRBbundle use the same precoder for a corresponding PDSCH transmission froma serving eNB 110. Each PRB bundle may have a number of associatedUE-specific RSs (for example, each PRB bundle may be associated with 12UE-specific RSs). In such embodiments, the UE 105 may perform a timefrequency tracking operation using a UE-specific RS transmittedindividually on each antenna port. The time frequency operation may beused to determine a time frequency offset for each UE-specific RSantenna port of each transmission point. In some embodiments, the timefrequency offset for each UE-specific RS antenna port and/ortransmission point may be computed by joint processing of the PRBsbundled in a PRB bundling set. Using the time frequency offset, the UE105 may determine UE-specific RSs for a set of PRBs transmitted from atransmission point.

When the indication is to indicate an appropriate QCL assumption to beused, the indication may indicate that individual transmittedUE-specific RS antenna ports (for example, antenna ports 7-14) are quasico-located with one or more antenna ports associated with one or moreother RSs. The other RSs may include one or more CRS (for example,antenna ports 0-3), one or more CSI-RS antenna ports (for example,antenna ports 15-22), and/or one or more discovery RS antenna ports(which may be used for discovering signals broadcast by a smallcell basestation). In such embodiments, the eNB 110 may configure the UE 105 withan appropriate QCL assumption. For example, the eNB 110 may provideconfiguration information through RRC signaling or through physicallayer signaling. For instance, the QCL assumptions may be indicated to aUE 105 using a “PDSCH resource element (RE) Mapping andQuasi-Co-Location” indicator field included in a DCI format 2D messageor a new DCI format message (for example, a DCI format 2E message).Furthermore, in some embodiments, two or more “PDSCH RE Mapping andQuasi-Co-Location Indicator” fields may be used in a DCI format 2Dmessage to indicate two or more QCL assumptions between subsets ofscheduled UE-specific RS antenna ports with CSI-RS antenna ports and/orCRS antenna ports. In other embodiments, two or more DCI messages may besent to the UE 105, where each DCI message may indicate one or moreparameters associated with the transmission from a correspondingtransmission point. In such embodiments, the one or more parameters mayinclude a QCL assumption between one or more UE-specific RS antennaports and a higher layer configured CRS resource and/or a CSI-RSresource associated with a transmission point.

By way of example, at operation 415 the UE 105 may receive one or moreDCI Format 2D messages, each of which may include a “PDSCH RE mappingand Quasi Co-Location Indicator” field. At operation 420, the UE 105 maydetermine a resource element mapping using the information contained inthe two or more “PDSCH RE Mapping and Quasi-Co-Location Indicator”fields. For example, when the UE 105 is configured in transmission mode10 for a given serving cell 115, the UE 105 may be configured with up tofour (4) parameter sets by higher layer signaling to decode PDSCHtransmission(s) according to a detected PDCCH/enhanced physical downlinkcontrol channel (EPDCCH) transmission(s) with DCI format 2D intended forthe UE 105 and the given serving cell 115. The UE 105 may use theparameter set according to the value of the “PDSCH RE Mapping andQuasi-Co-Location Indicator” field in the detected DCI format 2D messagefor determining a PDSCH RE mapping. The values of the “PDSCH RE Mappingand Quasi-Co-Location Indicator” field may be as follows.

TABLE 1 PDSCH RE Mapping and Quasi-Co-Location Indicator field in DCIformat 2D Value of “PDSCH RE Mapping and Quasi-Co-Location Indicator”field Description ‘00’ Parameter set 1 configured by higher layers ‘01’Parameter set 2 configured by higher layers ‘10’ Parameter set 3configured by higher layers ‘11’ Parameter set 4 configured by higherlayers

The parameters for determining PDSCH RE mapping and PDSCH antenna portquasi co-location are configured via higher layer signaling for eachparameter set include “crs-PortsCount-r11,” “crs-FreqShift-r11,”“mbsfn-SubframeConfigList-r11,” “csi-RS-ConfigZPId-r11,”“pdsch-Start-r11,” and “qcl-CSI-RS-ConfigNZPId-r11.”

In addition to determining a PDSCH RE mapping using the parameter setaccording to the value of the “PDSCH RE Mapping and Quasi-Co-LocationIndicator” field, the UE 105 may use the value contained in the “PDSCHRE mapping and Quasi Co-Location Indicator” fields to determine the oneor more other RSs that are quasi co-located with one or more UE-specificRSs. For instance, the UE 105 may use the indicated parameter set fordetermining PDSCH antenna port quasi co-location if the UE 105 isconfigured as a “Type B” quasi co-location type. For instance, accordingto current standards, a UE configured in transmission mode 10 for aserving cell is configured with one of two quasi co-location types (forexample, type A and type B) for the serving cell by higher layerparameter “qcl-Operation” to decode PDSCH transmissions according totransmission scheme associated with antenna ports 7-14. When the UE 105is configured as a type A UE, the UE 105 may assume the antenna ports0-3 and/or 7-22 of a serving cell are quasi co-located with respect todelay spread, Doppler spread, Doppler shift, and average delay. When theUE 105 is configured as a type B UE, the UE 105 may assume the antennaports 15-22 corresponding to the CSI-RS resource configurationidentified by the higher layer parameter “qcl-CSI-RS-ConfigNZPId-r11”and the antenna ports 7-14 associated with the PDSCH are quasico-located with respect to Doppler shift, Doppler spread, average delay,and delay spread.

According to various embodiments, the value of the “PDSCH RE Mapping andQuasi-Co-Location Indicator” field may also be used to indicate thePDSCH RE mapping pattern for a transmitting cell. For example, theresource elements used by CRS antenna ports may depend upon a physicalcell ID or a multicast/broadcast over a single frequency network (MBSFN)subframe configuration. In these cases, the PDSCH RE mapping may bedetermined by the number of CRS antenna ports, a CRS shift in frequency,and/or a MBSFN subframe configuration. The PDSCH REs may also depend onthe number of orthogonal frequency-division multiplexing (OFDM) symbolsused for control channel transmission. Furthermore, CSI-RS transmissionsmay also be different for different cells and/or transmission points,and therefore, CSI-RS resource configuration may also be used fordetermination of the PDSCH REs. As part of PDSCH RE mapping, a set ofquasi co-located CRS and CSI-RS antenna ports may be provided toindicate one or more reference signals that may be used for estimationof time-frequency offsets corresponding to a transmission point. Theestimated offsets may be compensated on the received PDSCH andUE-specific RS using a suitable timing and frequency offset compensationfunction.

FIG. 5 illustrates a process 500 that may be performed by a UE 105 todetermine QCL assumptions for multi-cell, multi-point SU-MIMOtransmissions, in accordance with various embodiments. In someembodiments, the UE 105 may include one or more non-transitorycomputer-readable media having instructions, stored thereon, that whenexecuted by the UE 105, cause the UE 105 to perform the process 500. Forillustrative purposes, the operations of process 500 will be describedas being performed by the UE 105, which is described with respect toFIGS. 1-3. However, it should be noted that other similar devices mayoperate the process 500. While particular examples and orders ofoperations are illustrated in FIG. 5, in various embodiments, theseoperations may be re-ordered, broken into additional operations,combined, and/or omitted altogether. In some embodiments, the operationsillustrated in FIG. 5 may be combined with operations described withregard to other embodiments, such as those illustrated by one or more ofFIGS. 4 and 6-8 and/or one or more operations described with regard tothe non-limiting examples provided herein.

Referring to FIG. 5, at operation 505 the UE 105 may control receptionof a first set of one or more independent data streams in a downlinkchannel of a first transmission point that is associated with a servingcell 115. At operation 510, the UE 105 may control reception of a secondset of one or more independent data streams in a downlink channel of asecond transmission point that is associated with a non-serving cell115. At least one individual data stream of the first set of one or moreindependent data streams may correspond to an individual layer, and theindependent data stream may be transmitted by at least one UE-specificRS antenna port (for example, one or more of antenna ports 7-14) of thefirst transmission point.

At operation 515, the UE 105 may control reception of controlinformation from the first transmission point and/or the secondtransmission point using one or more reception antenna elements. Atoperation 520, the UE 105 may determine a QCL assumption to be used forestimating channel characteristics for reception of the first set of oneor more independent data streams or for reception of the second set ofone or more independent data streams. In various embodiments, thecontrol information may include an indication of a parameter of thefirst or second set of one or more independent data streams. Theparameter may be indicative of a QCL assumption to be used forestimating channel characteristics of the downlink channels providingthe first or second set of one or more independent data streams. Atoperation 525, the UE 105 may estimate, using the quasi co-locationassumption, channel characteristics for reception of the first set ofone or more independent data streams or for reception of the second setof one or more independent data streams. The channel characteristics mayinclude Doppler shift, Doppler spread, average delay, and/or delayspread. In some embodiments, the parameter may indicate that no QCLassumption is to be used and that the UE 105 may assume the same channelcharacteristics across a defined set of PRBs (as discussed with regardto FIG. 4).

According to various embodiments, the indication (or parameter) mayindicate an appropriate QCL assumption to be used. For example, theindication (or parameter) may indicate that one or more UE-specific RSantenna ports may be quasi co-located with antenna ports associated withone or more other reference signal(s). The other reference signals mayinclude one or more CRS antenna ports (for example, antenna ports 0-3),one or more CSI-RS antenna ports (for example, antenna ports 15-22),and/or one or more discovery RSs.

In some embodiments, two or more PDSCH REs mapping sets may be providedto the UE 105 so that the UE 105 may determine PDSCH REs mappingassumptions for each MIMO layer transmitted by the correspondingtransmission point. For instance, the position of PDSCH REs within asubframe may depend on the REs occupied by one or more CRSs, which maybe based on a cell ID of a transmission point or cell 115. In somecases, if the transmission of PDSCH on MIMO layers is performed frommultiple transmission points, where each transmission point has adifferent cell ID, the PDSCH REs positions may not be aligned acrosseach of the multiple transmission points. Therefore, in someembodiments, two or more PDSCH REs mapping sets may be signaled to theUE 105 to determine the PDSCH REs mapping assumptions associated witheach MIMO layer(s) transmitted by the transmission point. In someembodiments, the two or more PDSCH REs mapping sets may be used todetermine the PDSCH REs assumptions for MIMO layers associated withUE-specific RS antenna ports. In such embodiments, the two or more PDSCHREs mapping sets may be provided to the UE 105 using two or more “PDSCHRE Mapping and Quasi-Co-Location Indicator” fields in two or more DCImessages. In such embodiments, each “PDSCH RE Mapping andQuasi-Co-Location Indicator” field may provide an association ofscheduled MIMO layers (UE-specific RS antenna ports) with a PDSCH REmapping. In other embodiments, two or more DCI Format 2D messages may besent to the UE 105 to indicate transmission parameters for scheduledlayers including their UE specific RS antenna ports and their PDSCH REsmapping.

FIG. 6 illustrates a process 600 that may be performed by a UE 105 todetermine QCL assumptions for multi-cell, multi-point SU-MIMOtransmissions, in accordance with various embodiments. In someembodiments, the UE 105 may include one or more non-transitorycomputer-readable media having instructions, stored thereon, that whenexecuted by the UE 105, cause the UE 105 to perform the process 600. Forillustrative purposes, the operations of process 600 will be describedas being performed by the UE 105, which is described with respect toFIGS. 1-3. However, it should be noted that other similar devices mayoperate the process 600. While particular examples and orders ofoperations are illustrated in FIG. 6, in various embodiments, theseoperations may be re-ordered, broken into additional operations,combined, and/or omitted altogether. In some embodiments, the operationsillustrated in FIG. 6 may be combined with operations described withregard to other embodiments, such as those illustrated by one or more ofFIGS. 4-5 and 7-8 and/or one or more operations described with regard tothe non-limiting examples provided herein.

Referring to FIG. 6, at operation 605 the UE 105 may receive two or moresets of parameters associated with PDSCH transmissions, wherein each setof parameters corresponds to an individual transmission point. Atoperation 610, the UE 105 may receive an indication of one or moretransmitted layers and an association of the transmission layers withone or more of the sets of parameters. At operation 615, the UE 105 mayreceive the PDSCH transmissions in accordance with the sets ofparameters.

A PDSCH parameter set may be used to derive PDSCH REs, which are used bya transmission point to transmit PDSCH transmissions. In someembodiments, a PDSCH parameter set may contain the CRS parameters, suchas a CRS shift, cell identity, a number of CRS antenna ports, and thelike. In some embodiments, a PDSCH parameter set may contain parametersof non-zero power channel state information reference signals (NZPCSI-RSs), such as number of NZP CSI-RS antenna ports, a scramblingidentity, a pattern index, and/or the like. In some embodiments, a PDSCHparameter set may be used to establish a QCL assumption of CRS antennaports and/or NZP CSI-RS antenna ports with UE-specific RS antenna ports.In such embodiments, the QCL assumption may be used to derive channelcharacteristics, such as delay spread, Doppler spread, time offset,frequency offset, and/or average channel gain.

Each set of parameters may be signaled to the UE 105 using higher layersignaling, such as using RRC signaling. Additionally, each PDSCHparameter set may be provided to the UE 105 on a per-transport blockbasis. In some embodiments, transport blocks may be transmitted fromdifferent transmission points, and in some cases, from the sametransmission point. Since different transmission points may havedifferent PDSCH REs, a parameter may be included in the “PDSCH REMapping and Quasi-Co-Location Indicator” field of one or more DCImessages for each transport block. The “PDSCH RE Mapping andQuasi-Co-Location Indicator” field may include 2 bits in a DCI format 2Dmessage as discussed above with regard to FIG. 4. In other embodiments,a new DCI format (for example, a DCI Format 2E) message may be used toindicate a QCL assumption. The new DCI format may also include a “PDSCHRE Mapping and Quasi-Co-Location Indicator” field to indicate the QCLassumptions, or the new DCI format may include another suitable fieldfor indicating the QCL assumption(s).

The per-transport block indication may allow for QCL associations ofUE-specific RS antenna ports with different CSI-RSs and/or CRSstransmitted by different transmission points. Such QCL associations maybe used for time frequency offset measurements and compensationaccording to a suitable time frequency offset estimation function. Theexample of the association between layers and 1st and 2nd “PDSCH REMapping and Quasi-Co-Location Indicator” fields is shown below for totalnumber of layers 2-8.

TABLE 2 Association between layers and 1st and 2nd antenna ports 1st{PDSCH REs, QCL-ed 2^(nd) {PDSCH REs, QCL-ed Total CRS, CSI-RS} for thelayers CRS, CSI-RS} for the layers Number transmitted on antennatransmitted on antenna of Layers ports (Transport block 1) ports(Transport block 2 2 7 8 3 7-8 9 4 7-8  9-10 5 7-9 10-11 6 7-9 10-12 7 7-10 11-13 8  7-10 11-14

Table 2 shows the quasi co-location of CRS antenna ports and/or CSI-RSantenna ports for layers to be transmitted on the specified antennaports. For example, if a PDSCH transmission with a total of 8 layers isscheduled for transmission, then a set of first layers transmitted onantenna ports 7-10 may be quasi co-located with first CRS antenna portsand/or CSI-RS antenna ports, and a set of second layers transmitted onantenna ports 11-14 may be quasi co-located with second CRS antennaports and/or CSI-RS antenna ports. To simplify processing of thereceived PDSCH transmissions, in some embodiments, some parametersassociated with “PDSCH RE Mapping and Quasi Co-Location Indicator”fields may be the same across two or more transport blocks. For example,in such embodiments, the UE 105 may assume a same PDSCH starting symbolfor two transport blocks, which may be set in accordance to the first(or second) “PDSCH RE Mapping and Quasi-Co-Location Indicator” field.

In other embodiments, “PDSCH RE Mapping and Quasi Co-Location Indicator”fields may provide information about PDSCH RE mapping on differentlayers, and the QCL information for the layers associated withUE-specific RS antenna ports may not be provided. In this case,UE-specific RS antenna ports used to transmit layers of differenttransport blocks may not be assumed to be quasi co-located. Instead, theUE 105 may assume that UE-specific RS antenna ports used to transmitlayers of one transport block are quasi co-located. The time-frequencytracking in this case should be performed by the UE 105 independently ondifferent groups of UE-specific RS. For example, in accordance withtable 2, if PDSCH transmission with 4 layers is scheduled, the UE 105may assume QCL of antenna ports 7 and 8 or QCL of antenna ports 9 and10, but not between antenna ports 7-8 and 9-10. Such embodiments arebased on an assumption that UE-specific RS antenna ports are not quasico-located with one another. This assumption may correspond to new QCLbehavior that may be configured to the UE 105 via higher layersignaling, such as RRC signaling. In such embodiments, the UE 105 mayassume that there are no QCL assumptions only when the size of resourceallocation is above N resource blocks, wherein N=2 or N=3. In otherembodiments, the UE 105 may assume QCL between UE-specific and otherreference signals such as CRS and/or CSI-RS, e.g., corresponding to theserving cell.

FIG. 7 illustrates a process 700 that may be performed by an eNB 110 todetermine and provide QCL assumptions for multi-cell, multi-pointSU-MIMO transmissions, in accordance with various embodiments. In someembodiments, the eNB 110 may include one or more non-transitorycomputer-readable media having instructions, stored thereon, that whenexecuted by the eNB 110, cause the eNB 110 to perform the process 700.For illustrative purposes, the operations of process 700 will bedescribed as being performed by the eNB 110, which is described withrespect to FIGS. 1-3. However, it should be noted that other similardevices and/or network elements may operate the process 700. Whileparticular examples and orders of operations are illustrated in FIG. 7,in various embodiments, these operations may be re-ordered, broken intoadditional operations, combined, and/or omitted altogether. In someembodiments, the operations illustrated in FIG. 7 may be combined withoperations described with regard to other embodiments, such as thoseillustrated by FIGS. 4-6 and 8 and/or one or more operations describedwith regard to the non-limiting examples provided herein.

Referring to FIG. 7, at operation 705 the eNB 110 may identify controlinformation related to a parameter of a first independent data streamthat is to be transmitted by a downlink cell associated with the eNB 110or a second independent data stream that is to be transmitted by anotherdownlink cell that is associated with another eNB 110. At operation 710,the eNB 110 may transmit the control information that includes anindication of the parameter to a UE 105 so that the UE 105 may determineparameters of downlink transmissions. In various embodiments, theparameter may be indicative of a QCL assumption to be used fordetermining channel characteristics for obtaining the first independentdata stream or the second independent data stream. For example, in someembodiments, CSI-RS antenna ports may not be assumed to be quasico-located with one another, and the eNB 110 may use channel stateinformation (CSI) to assist the transmission of the first set of one ormore independent data streams. In such embodiments, the controlinformation may configure a UE 105 with one of two CSI processes, atransmission point-specific CSI feedback process or an aggregated CSIfeedback process.

In the transmission point-specific CSI feedback process, the CSIfeedback for multi-point, multi-cell SU-MIMO operation may includeconfiguring the UE 105 with two or more CSI reporting processes, whereeach CSI reporting process contains one NZP CSI-RS resource for channelmeasurement associated with one transmission point. Each CSI process mayrepresent CSI for one link 120 between the UE 105 and a transmissionpoint. In such embodiments, for each link 120, the UE 105 may provideCSI feedback (for example, channel quality indicator (CQI), precodingmatrix indicator (PMI), rank indicator (RI), and/or the like) to acorresponding transmission point. In some embodiments, CQI reporting maybe provided for aggregated CSI-RS resource, which is combined from a setof CSI-RS resources configured for the UE 105. The CSI-RS resourceaggregation may be provided by signaling the CSI-RS resource indexes tothe UE 105. Furthermore, each CSI feedback process may yield differentRI values, and under current standards, a first CSI feedback process mayinherit the RI values from a second CSI feedback process. In suchembodiments, the RI values of the second CSI feedback may be assumed forfirst CSI feedback process, while the PMI and CQI would be determinedindependently among the CSI feedback processes. In various embodiments,an indication of the RI inheritance from a corresponding CSI feedbackprocesses may be also provided to another CSI feedback process tocalculate CQI based on the assumption that precoding using PMIs werecalculated for the CSI feedback processes. The CQI with aggregatedCSI-RS resources may be derived as an average CQI, where the averagingis performed across different phases between CSI-RS resources thatcomprise the aggregated CSI-RS resource.

In the aggregated CSI feedback process, one CSI reporting process isused, where the CSI process contains a CSI-RS resource with antennaports transmitted from all antenna elements of the two or moretransmission points. In this case the existing QCL assumption for CSI-RSresource should be relaxed and the UE shall not assume quasi co-locationbetween antenna ports of one CSI-RS resource. In another embodiment,higher layer signaling may be used to indicate whether the QCLassumption for a given CSI-RS resource is valid or not. The eNB 110 mayidentify and transmit to the UE 105 an indication related to aggregationof CSI-RS antenna ports to be used for CSI reporting in higher layersignaling, for example, RRC signaling.

According to various embodiments, generating the control information mayinclude a codeword to layer mapping to help control data rateassignments for each transmission layer. For instance, one or moretransport blocks may be converted into a codeword, which may be used toobtain one or more modulation symbols. These modulation symbols may thenbe mapped to one or more antenna ports. In some embodiments, where twoor more DCI messages are used to schedule PDSCH transmissions, the eNB110 may map each codeword to an individual transmission layer, such thatthere is a one-to-one correspondence between each codeword and eachlayer. In other embodiments, the eNB 110 may map a plurality of layersto each codeword, which may reduce signaling overhead associated withindicating the modulation and coding scheme.

Referring back to FIG. 7, once the control information is identified andtransmitted to the UE 105, at operation 715, the eNB 110 may transmit afirst set of one or more independent data streams in a downlink channel.

FIG. 8 illustrates a process 800 that may be performed by an eNB 110 todetermine and provide QCL assumptions for multi-cell, multi-pointSU-MIMO transmissions, in accordance with various embodiments. In someembodiments, the eNB 110 may include one or more non-transitorycomputer-readable media having instructions, stored thereon, which whenexecuted by the eNB 110, cause the eNB 110 to perform the process 800.For illustrative purposes, the operations of process 800 will bedescribed as being performed by the eNB 110, which is described withrespect to FIGS. 1-3. However, it should be noted that other similardevices and/or network elements may operate the process 800. Whileparticular examples and orders of operations are illustrated in FIG. 8,in various embodiments, these operations may be re-ordered, broken intoadditional operations, combined, and/or omitted altogether. In someembodiments, the operations illustrated in FIG. 8 may be combined withoperations described with regard to other embodiments, such as thoseillustrated by one or more of FIGS. 4-7 and/or one or more operationsdescribed with regard to the non-limiting examples provided herein.

Referring to FIG. 8, at operation 805 the eNB 110 may generate a set ofindependent data streams to be transmitted in a downlink channel from anassociated transmission point. In various embodiments, the transmissionpoint associated with the eNB 110 may correspond with a downlink cell115 or one or more physical transmission antenna elements. At operation810, the eNB 110 may control transmission of the set of independent datastreams to the UE 105 using the one or more transmission antennaelements. Each independent data stream may correspond to a single layer,and each independent data stream may be transmitted using at least oneantenna port associated with one or more UE-specific RSs (for example,one or more of antenna ports 7-14). The eNB 110 may receive CSI feedbackfrom the UE 105, which may be used by the eNB 110 to generate andtransmit the independent data streams. In such embodiments, the eNB 110may configure the UE 105 with one of two CSI processes, such as thetransmission point-specific CSI feedback process or the aggregated CSIfeedback process as discussed previously with regard to FIG. 7.

At operation 815, the eNB 110 may generate control informationassociated with the transmission point or another transmission pointindicating parameters for the set of independent data streams. Atoperation 820, the eNB 110 may cause transmission of the controlinformation using one or more transmission antenna elements. Theparameters may be indicative of a quasi co-location assumption to beused for reception of the set of independent data streams. In variousembodiments, transmitting the control information may include signalingthe quasi co-location of the UE-specific RS antenna ports with one ormore other reference signals using two or more “PDSCH RE Mapping andQuasi-Co-Location Indicator” fields according to the various exampleembodiments described previously. Furthermore, in some embodiments, theeNB 110 may generate the control information by mapping one codeword toone transmission layer when two or more DCI messages are to be used toschedule a PDSCH transmission. In other embodiments, the eNB 110 may mapone codeword to two or more transmission layers associated with one ormore independent data streams of the first set of one or moreindependent data streams or map one codeword to two or more layersassociated with one or more independent data streams of the second setof one or more independent data streams. In either embodiment, thecontrol information may indicate whether there is a one-to-onecorrespondence between each codeword and each transmission layer, or ifthere is a one-to-many correspondence between each codeword and two ormore transmission layers.

The foregoing description of the above implementations providesillustration and description for the example embodiments, but is notintended to be exhaustive or to limit the scope of the invention to theprecise form disclosed. Modifications and variations are possible inlight of the above teachings and/or may be acquired from practice ofvarious implementations of the invention. For example, the describedexample embodiments pertain to facilitating multi-cell, multi-pointSU-MIMO transmissions. However, the example embodiments may be extendedto be applicable for facilitating multi-cell, multi-point multiple user(MU)-MIMO transmissions, for example.

Some non-limiting examples are provided below.

Example 1 may include at least one computer-readable medium includinginstructions that, when executed by one or more processors, cause a userequipment (UE) to: process a first set of one or more independent datastreams received in a downlink channel from a first transmission point;process a second set of one or more independent data streams received ina downlink channel from a second transmission point; process controlinformation received from the first transmission point or the secondtransmission point; determine a quasi co-location assumption to be usedfor estimating channel characteristics for reception of the first set ofone or more independent data streams or for reception of the second setof one or more independent data streams, wherein the quasi co-locationassumption to be used is based on an indication within the controlinformation; and estimate channel characteristics for reception of thefirst set of one or more independent data streams or for reception ofthe second set of one or more independent data streams according to thequasi co-location assumption. The at least one computer-readable mediummay be a non-transitory computer-readable medium.

Example 2 may include the at least one computer-readable medium ofexample 1 and/or any other one or more examples disclosed herein,wherein at least one independent data stream of the first set of one ormore independent data streams corresponds to a first layer, and the atleast one independent data stream is to be transmitted by at least oneantenna port of a plurality of antenna ports associated with one or moreUE-specific reference signals (RSs) of the first transmission point.

Example 3 may include the at least one computer-readable medium ofexample 2 and/or any other one or more examples disclosed herein,wherein the indication is to indicate that the plurality of antennaports are not assumed to be quasi co-located with respect to at leastone of a Doppler shift, a Doppler spread, an average delay, or a delayspread.

Example 4 may include the at least one computer-readable medium ofexample 3 and/or any other one or more examples disclosed herein,wherein a same Doppler shift, Doppler spread, average delay, and delayspread are assumed over a predefined set of physical resource blocks(PRBs).

Example 5 may include the at least one computer-readable medium ofexample 3 and/or any other one or more examples disclosed herein,wherein the indication is to indicate that antenna ports of theplurality of antenna ports associated with the one or more UE-specificRSs are quasi co-located with one or more antenna ports associated withone or more other RSs.

Example 6 may include the at least one computer-readable medium ofexample 5 and/or any other one or more examples disclosed herein,wherein the one or more other RSs include one of cell specific RSs(CRSs), channel state information reference signals (CSI-RSs), ordiscovery RSs.

Example 7 may include the at least one computer-readable medium ofexample 2 and/or any other one or more examples disclosed herein,wherein the indication is to indicate quasi co-location of antenna portsof the plurality of antenna ports associated with the one or moreUE-specific RSs with other RSs, and wherein the instructions, whenexecuted by the one or more processors, cause the UE to: determine theone or more other RSs using two or more physical downlink shared channel(PDSCH) resource element (RE) mapping and Quasi Co-Location Indicatorfields.

Example 8 may include the at least one computer-readable medium ofexample 2 and/or any other one or more examples disclosed herein,wherein the indication is to indicate quasi co-location of antenna portsof the plurality of antenna ports associated with the one or moreUE-specific RSs with other RSs, and wherein the instructions, whenexecuted by the one or more processors, cause the UE to: determine theone or more other RSs using two or more downlink control information(DCI) format 2D messages, wherein each of the two or more DCI format 2Dmessages include at least one PDSCH RE mapping and Quasi Co-LocationIndicator field.

Example 9 may include the at least one computer-readable medium ofexample 2 and/or any other one or more examples disclosed herein,wherein the indication is to indicate an RE mapping for the one or moreindependent data streams of the first set of one or more independentdata streams and the one or more independent data streams of the secondset of one or more independent data streams, and wherein theinstructions, when executed by the one or more processors, cause the UEto: determine the RE mapping using two or more PDSCH RE Mapping andQuasi-Co-Location Indicator fields.

Example 10 may include an apparatus to be implemented in a userequipment (UE) comprising: an antenna array that includes at least afirst receive antenna and a second receive antenna; one or morecomputer-readable storage media having instructions; and one or moreprocessors coupled with the antenna array and the one or morecomputer-readable storage media, wherein at least one processor of theone or more processors is to execute the instructions to: controlreception of a first set of one or more independent data streams in adownlink channel of a first cell using the first receive antennas;control reception of a second set of one or more independent datastreams in a downlink channel of a second cell using the second receiveantennas; control reception of control information from a first downlinkcell using the first receive antennas or a second downlink cell usingthe second receive antennas; determine a quasi co-location assumptionbased on an indication of the control information, wherein the quasico-location assumption is to be used for estimating channelcharacteristics for reception of the first set of one or moreindependent data streams or for reception of the second set of one ormore independent data streams; and estimate, using the quasi co-locationassumption, channel characteristics for reception of the first set ofone or more independent data streams or for reception of the second setof one or more independent data streams.

Example 11 may include the apparatus of example 10 and/or any other oneor more examples disclosed herein, wherein at least one independent datastream of the first set of one or more independent data streamscorresponds to one layer, and the at least one independent data streamis transmitted by at least one antenna port of a plurality of antennaports associated with one or more UE-specific reference signals of thefirst downlink cell, wherein the plurality of antenna ports includeantenna ports 7-14.

Example 12 may include the apparatus of example 11 and/or any other oneor more examples disclosed herein, wherein the indication is to indicatethat the plurality of antenna ports are not assumed to be quasico-located with respect to Doppler shift, Doppler spread, average delay,and/or delay spread, and a same Doppler shift, Doppler spread, averagedelay, and delay spread are to be assumed over a predefined set ofphysical resource blocks (PRBs).

Example 13 may include the apparatus of example 12, wherein the antennaports of the one or more UE-specific RS antenna ports is quasico-located with antenna ports associated with one or more other RSs,wherein the one or more other RSs include at least one of cell specificRSs including antenna ports 0-3, channel state information RSs (CSI-RSs)including antenna ports 15-21, or discovery RSs.

Example 14 may include the apparatus of example 11 and/or any other oneor more examples disclosed herein, wherein the control informationincludes an indication of quasi co-location of the plurality of antennaports associated with the one or more UE-specific reference signals withother reference signals using two or more physical downlink sharedchannel (PDSCH) resource element (RE) Mapping and Quasi-Co-LocationIndicator fields.

Example 15 may include the apparatus of example 11 and/or any other oneor more examples disclosed herein, wherein the indication is to indicatequasi co-location of the plurality of antenna ports associated with theone or more UE-specific RSs with other RSs, and the at least oneprocessor of the one or more processors is to execute the instructionsto: determine the other RSs using two or more downlink controlinformation formats 2D that include one PDSCH RE Mapping andQuasi-Co-Location Indicator field.

Example 16 may include the apparatus of example 11 and/or any other oneor more examples disclosed herein, wherein the indication is to indicatean RE mapping for the one or more independent data streams of the firstset of one or more independent data streams and the one or moreindependent data streams of the second set of one or more independentdata streams, and the at least one processor of the one or moreprocessors is to execute the instructions to: determine the RE mappingusing two or more PDSCH RE Mapping and Quasi-Co-Location Indicatorfields.

Example 17 may include the apparatus of example 10 and/or any other oneor more examples disclosed herein, wherein channel state information(CSI) is used by the first downlink cell or the second downlink cell toassist the transmission of the first set of one or more independent datastreams or the second set of one or more independent data streams andantenna ports associated with a CSI reference signal (CSI-RS) are notassumed as quasi co-located, and wherein the at least one processor isto execute the instructions to: control reception, in higher layersignaling, of an indication related to aggregation of the antenna portsof the configured CSI-RS that should be used for CSI reporting.

Example 18 may include at least one computer-readable medium includinginstructions to cause an evolved node B (eNB), in response to executionof the instructions by the eNB, to: cause transmission of a first set ofone or more independent data streams in a downlink channel from a firsttransmission point associated with the eNB, wherein the firsttransmission point corresponds to a downlink cell and a secondtransmission point is one of another eNB or a smallcell base station;generate control information that includes an indication of a parameterof at least one of the first set of one or more independent data streamsor a second set of one or more independent data streams to betransmitted by the second transmission point in a downlink channel ofthe second transmission point; and cause transmission of the controlinformation. The at least one computer-readable medium may be anon-transitory computer-readable medium.

Example 19 may include the at least one computer-readable medium ofexample 18 and/or any other one or more examples disclosed herein,wherein antenna ports associated with a CSI reference signal (CSI-RS)are not assumed as quasi co-located, and wherein the instructionsfurther cause the eNB, in response to execution of the instructions bythe eNB, to: use channel state information (CSI) to assist thetransmission of the first set of one or more independent data streams;and transmit, in higher layer signaling, an indication related toaggregation of antenna ports of configured CSI-RSs to be used for CSIreporting.

Example 20 may include the at least one computer-readable medium ofexample 18 and/or any other one or more examples disclosed herein,wherein the instructions further cause the eNB, in response to executionof the instructions by the eNB, to: map one codeword to one transmissionlayer when two or more downlink control information (DCI) messages areto be used to schedule a physical downlink shared channel (PDSCH).

Example 21 may include the at least one computer-readable medium ofexample 18 and/or any other one or more examples disclosed herein,wherein the instructions further cause the eNB, in response to executionof the instructions by the eNB, to: map one codeword to two or moretransmission layers associated with one or more independent data streamsof a first set of one or more independent data streams or map onecodeword to two or more layers associated with one or more independentdata streams of a second set of one or more independent data streams.

Example 22 may include an apparatus to be implemented in an evolved nodeB (eNB) comprising: one or more computer-readable storage media havinginstructions; and one or more processors coupled with an antenna arrayand the one or more computer-readable storage media, wherein at leastone processor of the one or more processors is to execute theinstructions to: identify control information related to a parameter ofa first independent data stream that is to be transmitted by a downlinkcell or a second independent data stream that is to be transmitted byanother downlink cell; and cause transmission of the first independentdata stream and the control information.

Example 23 may include the apparatus of example 22 and/or any other oneor more examples disclosed herein, wherein antenna ports associated witha CSI reference signal (CSI-RS) are not assumed as quasi co-located, andwherein the at least one processor is to execute the instructions to:use channel state information (CSI) to assist the transmission of thefirst independent data stream; and transmit, in higher layer signaling,an indication related to aggregation of antenna ports of configuredCSI-RSs to be used for CSI reporting.

Example 24 may include the apparatus of example 22 and/or any other oneor more examples disclosed herein, wherein the at least one processor isto execute the instructions to: map one codeword to one transmissionlayer when two or more downlink control information (DCI) messages areto be used to schedule a physical downlink shared channel (PDSCH).

Example 25 may include the apparatus of example 22 and/or any other oneor more examples disclosed herein, wherein the at least one processor isto execute the instructions to: map one codeword to two or more layersassociated with one or more independent data streams including the firstindependent data stream or map one codeword to two or more layersassociated with one or more independent data streams of including thesecond independent data stream.

Example 26 may include an apparatus to be implemented in a userequipment (UE) comprising: radio frequency (RF) circuitry to receive, ina first downlink channel, a first set of one or more independent datastreams received from a first transmission point; receive, in a seconddownlink channel, a second set of one or more independent data streamsfrom a second transmission point; and receive control information fromthe first transmission point or the second transmission point; andbaseband circuitry to process the first set of one or more independentdata streams; process the second set of one or more independent datastreams; process the control information to determine a quasico-location assumption to be used for estimating channel characteristicsfor reception of the first set of one or more independent data streamsor for reception of the second set of one or more independent datastreams, wherein the quasi co-location assumption to be used is based onan indication within the control information; and estimate channelcharacteristics for reception of the first set of one or moreindependent data streams or for reception of the second set of one ormore independent data streams according to the quasi co-locationassumption.

Example 27 may include the apparatus of example 26 and/or any other oneor more examples disclosed herein, wherein at least one independent datastream of the first set of one or more independent data streamscorresponds to a first layer, and the at least one independent datastream is to be transmitted by at least one antenna port of a pluralityof antenna ports associated with one or more UE-specific referencesignals (RSs) of the first transmission point.

Example 28 may include the apparatus of example 27 and/or any other oneor more examples disclosed herein, wherein the indication is to indicatethat the plurality of antenna ports are not assumed to be quasico-located with respect to at least one of a Doppler shift, a Dopplerspread, an average delay, or a delay spread.

Example 29 may include the apparatus of example 28 and/or any other oneor more examples disclosed herein, wherein a same Doppler shift, Dopplerspread, average delay, and delay spread are assumed over a predefinedset of physical resource blocks (PRBs).

Example 30 may include the apparatus of example 28 and/or any other oneor more examples disclosed herein, wherein the indication is to indicatethat antenna ports of the plurality of antenna ports associated with theone or more UE-specific RSs are quasi co-located with one or moreantenna ports associated with one or more other RSs.

Example 31 may include the apparatus of example 30 and/or any other oneor more examples disclosed herein, wherein the one or more other RSsinclude one of cell specific RSs (CRSs), channel state informationreference signals (CSI-RSs), or discovery RSs.

Example 32 may include the apparatus of example 27 and/or any other oneor more examples disclosed herein, wherein the indication is to indicatequasi co-location of antenna ports of the plurality of antenna portsassociated with the one or more UE-specific RSs with other RSs, andwherein the baseband circuitry is to determine the one or more other RSsusing two or more physical downlink shared channel (PDSCH) resourceelement (RE) mapping and Quasi Co-Location Indicator fields.

Example 33 may include the apparatus of example 27 and/or any other oneor more examples disclosed herein, wherein the indication is to indicatequasi co-location of antenna ports of the plurality of antenna portsassociated with the one or more UE-specific RSs with other RSs, andwherein the baseband circuitry is to determine the one or more other RSsusing two or more downlink control information (DCI) format 2D messages,wherein each of the two or more DCI format 2D messages include at leastone PDSCH RE mapping and Quasi Co-Location Indicator field.

Example 34 may include the apparatus of example 27 and/or any other oneor more examples disclosed herein, wherein the indication is to indicatean RE mapping for the one or more independent data streams of the firstset of one or more independent data streams and the one or moreindependent data streams of the second set of one or more independentdata streams, and wherein the baseband circuitry is to determine the REmapping using two or more PDSCH RE Mapping and Quasi-Co-LocationIndicator fields.

Example 35 may include a computer-implemented method for providingmulti-cell, multi-point single user (SU) multiple input and multipleoutput (MIMO) transmissions, the method comprising: receiving andprocessing, by a user equipment (UE), a first set of one or moreindependent data streams received in a downlink channel from a firsttransmission point; receiving and processing, by the UE, a second set ofone or more independent data streams received in a downlink channel froma second transmission point; receiving and processing, by the UE,control information received from the first transmission point or thesecond transmission point; determining, by the UE, a quasi co-locationassumption to be used for estimating channel characteristics forreception of the first set of one or more independent data streams orfor reception of the second set of one or more independent data streams,wherein the quasi co-location assumption to be used is based on anindication within the control information; and estimating, by the UE,channel characteristics for reception of the first set of one or moreindependent data streams or for reception of the second set of one ormore independent data streams according to the quasi co-locationassumption.

Example 36 may include the method of example 35 and/or any other one ormore examples disclosed herein, wherein at least one independent datastream of the first set of one or more independent data streamscorresponds to a first layer, and the at least one independent datastream is to be transmitted by at least one antenna port of a pluralityof antenna ports associated with one or more UE-specific referencesignals (RSs) of the first transmission point.

Example 37 may include the method of example 36 and/or any other one ormore examples disclosed herein, wherein the indication indicates thatthe plurality of antenna ports are not assumed to be quasi co-locatedwith respect to at least one of a Doppler shift, a Doppler spread, anaverage delay, or a delay spread.

Example 38 may include the method of example 37 and/or any other one ormore examples disclosed herein, wherein a same Doppler shift, Dopplerspread, average delay, and delay spread are assumed over a predefinedset of physical resource blocks (PRBs).

Example 39 may include the method of example 37 and/or any other one ormore examples disclosed herein, wherein the indication indicates thatantenna ports of the plurality of antenna ports associated with the oneor more UE-specific RSs are quasi co-located with one or more antennaports associated with one or more other RSs.

Example 40 may include the method of example 39, wherein the one or moreother RSs include one of cell specific RSs (CRSs), channel stateinformation reference signals (CSI-RSs), or discovery RSs.

Example 41 may include the method of example 36 and/or any other one ormore examples disclosed herein, wherein the indication indicates quasico-location of antenna ports of the plurality of antenna portsassociated with the one or more UE-specific RSs with other RSs, and themethod further comprises: determining, by the UE, the one or more otherRSs using two or more physical downlink shared channel (PDSCH) resourceelement (RE) mapping and Quasi Co-Location Indicator fields.

Example 42 may include the method of example 36 and/or any other one ormore examples disclosed herein, wherein the indication indicates quasico-location of antenna ports of the plurality of antenna portsassociated with the one or more UE-specific RSs with other RSs, and themethod further comprises: determining, by the UE, the one or more otherRSs using two or more downlink control information (DCI) format 2Dmessages, wherein each of the two or more DCI format 2D messages includeat least one PDSCH RE mapping and Quasi Co-Location Indicator field.

Example 43 may include the method of example 36 and/or any other one ormore examples disclosed herein, wherein the indication indicates an REmapping for the one or more independent data streams of the first set ofone or more independent data streams and the one or more independentdata streams of the second set of one or more independent data streams,and the method further comprises: determining, by the UE, the RE mappingusing two or more PDSCH RE Mapping and Quasi-Co-Location Indicatorfields.

Example 44 may include at least one computer-readable medium includinginstructions to cause a user equipment (UE), in response to execution ofthe instructions by the UE, to perform the method of any one of examples35-43 and/or any other one or more examples disclosed herein. The atleast one computer-readable medium may be a non-transitorycomputer-readable medium.

Example 45 may include an apparatus to be implemented in a userequipment (UE) comprising: an antenna array that includes at least afirst receive antenna and a second receive antenna; radio frequency (RF)circuitry coupled with the antenna array, the RF circuitry to receive afirst set of one or more independent data streams in a downlink channelof a first cell using the first receive antennas; receive a second setof one or more independent data streams in a downlink channel of asecond cell using the second receive antennas; and receive controlinformation from a first downlink cell using the first receive antennasor a second downlink cell using the second receive antennas; andbaseband circuitry coupled with the RF circuitry, the baseband circuitryto determine a quasi co-location assumption based on an indication ofthe control information, wherein the quasi co-location assumption to beused for estimating channel characteristics for reception of the firstset of one or more independent data streams or for reception of thesecond set of one or more independent data streams; and estimate, usingthe quasi co-location assumption, channel characteristics for receptionof the first set of one or more independent data streams or forreception of the second set of one or more independent data streams.

Example 46 may include the apparatus of example 45 and/or any other oneor more examples disclosed herein, wherein at least one independent datastream of the first set of one or more independent data streamscorresponds to one layer, and the at least one independent data streamis transmitted by at least one antenna port of a plurality of antennaports associated with one or more UE-specific reference signals of thefirst downlink cell, wherein the plurality of antenna ports includeantenna ports 7-14.

Example 47 may include the apparatus of example 46 and/or any other oneor more examples disclosed herein, wherein the indication is to indicatethat the plurality of antenna ports are not assumed to be quasico-located with respect to Doppler shift, Doppler spread, average delay,and/or delay spread, and a same Doppler shift, Doppler spread, averagedelay, and delay spread are to be assumed over a predefined set ofphysical resource blocks (PRBs).

Example 48 may include the apparatus of example 47 and/or any other oneor more examples disclosed herein, wherein the antenna ports of the oneor more UE-specific RS antenna ports is quasi co-located with antennaports associated with one or more other RSs, wherein the one or moreother RSs include at least one of cell specific RSs including antennaports 0-3, channel state information RSs (CSI-RSs) including antennaports 15-21, or discovery RSs.

Example 49 may include the apparatus of example 46 and/or any other oneor more examples disclosed herein, wherein the control informationincludes an indication of quasi co-location of the plurality of antennaports associated with the one or more UE-specific reference signals withother reference signals using two or more physical downlink sharedchannel (PDSCH) resource element (RE) Mapping and Quasi-Co-LocationIndicator fields.

Example 50 may include the apparatus of example 46 and/or any other oneor more examples disclosed herein, wherein the indication is to indicatequasi co-location of the plurality of antenna ports associated with theone or more UE-specific RSs with other RSs, and the baseband circuitryis to determine the other RSs using two or more downlink controlinformation formats 2D that include one PDSCH RE Mapping andQuasi-Co-Location Indicator field.

Example 51 may include the apparatus of example 46 and/or any other oneor more examples disclosed herein, wherein the indication is to indicatean RE mapping for the one or more independent data streams of the firstset of one or more independent data streams and the one or moreindependent data streams of the second set of one or more independentdata streams, and the baseband circuitry is to determine the RE mappingusing two or more PDSCH RE Mapping and Quasi-Co-Location Indicatorfields.

Example 52 may include the apparatus of example 45 and/or any other oneor more examples disclosed herein, wherein channel state information(CSI) is used by the first downlink cell or the second downlink cell toassist the transmission of the first set of one or more independent datastreams or the second set of one or more independent data streams andantenna ports associated with a CSI reference signal (CSI-RS) are notassumed as quasi co-located, and the baseband circuitry is to controlreception, in higher layer signaling, of an indication related toaggregation of the antenna ports of the configured CSI-RS that should beused for CSI reporting.

Example 53 may include a computer-implemented method for providingmulti-cell, multi-point single user (SU) multiple input and multipleoutput (MIMO) transmissions, the method comprising: receiving, by a userequipment (UE), a first set of one or more independent data streams in adownlink channel of a first cell using first receive antennas;receiving, by the UE, a second set of one or more independent datastreams in a downlink channel of a second cell using second receiveantennas; receiving, by the UE, control information from a firstdownlink cell using the first receive antennas or a second downlink cellusing the second receive antennas; determining, by the UE, a quasico-location assumption based on an indication of the controlinformation, wherein the quasi co-location assumption to be used forestimating channel characteristics for reception of the first set of oneor more independent data streams or for reception of the second set ofone or more independent data streams; and estimating, by the UE, usingthe quasi co-location assumption, channel characteristics for receptionof the first set of one or more independent data streams or forreception of the second set of one or more independent data streams.

Example 54 may include the method of example 53 and/or any other one ormore examples disclosed herein, wherein at least one independent datastream of the first set of one or more independent data streamscorresponds to one layer, and the at least one independent data streamis transmitted by at least one antenna port of a plurality of antennaports associated with one or more UE-specific reference signals of thefirst downlink cell, wherein the plurality of antenna ports includeantenna ports 7-14.

Example 55 may include the method of example 54 and/or any other one ormore examples disclosed herein, wherein the indication is to indicatethat the plurality of antenna ports are not assumed to be quasico-located with respect to Doppler shift, Doppler spread, average delay,and/or delay spread, and a same Doppler shift, Doppler spread, averagedelay, and delay spread are to be assumed over a predefined set ofphysical resource blocks (PRBs).

Example 56 may include the method of example 55 and/or any other one ormore examples disclosed herein, wherein the antenna ports of the one ormore UE-specific RS antenna ports is quasi co-located with antenna portsassociated with one or more other RSs, wherein the one or more other RSsinclude at least one of cell specific RSs including antenna ports 0-3,channel state information RSs (CSI-RSs) including antenna ports 15-21,or discovery RSs.

Example 57 may include the method of example 54 and/or any other one ormore examples disclosed herein, wherein the control information includesan indication of quasi co-location of the plurality of antenna portsassociated with the one or more UE-specific reference signals with otherreference signals using two or more physical downlink shared channel(PDSCH) resource element (RE) Mapping and Quasi-Co-Location Indicatorfields.

Example 58 may include the method of example 54 and/or any other one ormore examples disclosed herein, wherein the indication is to indicatequasi co-location of the plurality of antenna ports associated with theone or more UE-specific RSs with other RSs, and at least one processorof one or more processors is to execute the instructions to: determinethe other RSs using two or more downlink control information formats 2Dthat include one PDSCH RE Mapping and Quasi-Co-Location Indicator field.

Example 59 may include the method of example 54 and/or any other one ormore examples disclosed herein, wherein the indication is to indicate anRE mapping for the one or more independent data streams of the first setof one or more independent data streams and the one or more independentdata streams of the second set of one or more independent data streams,and at least one processor of one or more processors is to execute theinstructions to: determine the RE mapping using two or more PDSCH REMapping and Quasi-Co-Location Indicator fields.

Example 60 may include the method of example 53 and/or any other one ormore examples disclosed herein, wherein channel state information (CSI)is used by the first downlink cell or the second downlink cell to assistthe transmission of the first set of one or more independent datastreams or the second set of one or more independent data streams andantenna.

Example 61 may include at least one computer-readable medium includinginstructions to cause a user equipment (UE), in response to execution ofthe instructions by the UE, to perform the method of any one of examples53-60 and/or any other one or more examples disclosed herein. The atleast one computer-readable medium may be a non-transitorycomputer-readable medium.

Example 62 may include an apparatus to be implemented by an evolved nodeB (eNB), comprising: one or more computer-readable storage media havinginstructions; and one or more processors coupled with an antenna arrayand the one or more computer-readable storage media, wherein at leastone processor of the one or more processors is to execute theinstructions to: cause transmission of a first set of one or moreindependent data streams in a downlink channel from a first transmissionpoint associated with the eNB, wherein the first transmission pointcorresponds to a downlink cell and a second transmission point is one ofanother eNB or a smallcell base station; generate control informationthat includes an indication of a parameter of at least one of the firstset of one or more independent data streams or a second set of one ormore independent data streams to be transmitted by the secondtransmission point in a downlink channel of the second transmissionpoint; and cause transmission of the control information.

Example 63 may include the apparatus of example 62 and/or any other oneor more examples disclosed herein, wherein antenna ports associated witha CSI reference signal (CSI-RS) are not assumed as quasi co-located, andwherein the instructions further cause the eNB, in response to executionof the instructions by the eNB, to: use channel state information (CSI)to assist the transmission of the first set of one or more independentdata streams; and transmit, in higher layer signaling, an indicationrelated to aggregation of antenna ports of configured CSI-RSs to be usedfor CSI reporting.

Example 64 may include the apparatus of example 62 and/or any other oneor more examples disclosed herein, wherein the instructions furthercause the eNB, in response to execution of the instructions by the eNB,to: map one codeword to one transmission layer when two or more downlinkcontrol information (DCI) messages are to be used to schedule a physicaldownlink shared channel (PDSCH).

Example 65 may include the apparatus of example 62 and/or any other oneor more examples disclosed herein, wherein the instructions furthercause the eNB, in response to execution of the instructions by the eNB,to: map one codeword to two or more transmission layers associated withone or more independent data streams of the first set of one or moreindependent data streams or map one codeword to two or more layersassociated with one or more independent data streams of the second setof one or more independent data streams.

Example 66 may include an apparatus to be implemented by an evolved nodeB (eNB), comprising: radio frequency (RF) circuitry to transmit a firstset of one or more independent data streams in a downlink channel from afirst transmission point associated with the eNB, wherein the firsttransmission point corresponds to a downlink cell and a secondtransmission point is one of another eNB or a smallcell base station;and baseband circuitry coupled with the RF circuitry, the basebandcircuitry to generate control information that includes an indication ofa parameter of at least one of the first set of one or more independentdata streams or a second set of one or more independent data streams tobe transmitted by the second transmission point in a downlink channel ofthe second transmission point, and wherein the RF circuitry is totransmit the control information.

Example 67 may include the apparatus of example 66 and/or any other oneor more examples disclosed herein, wherein antenna ports associated witha CSI reference signal (CSI-RS) are not assumed as quasi co-located, andwherein the baseband circuitry is to use channel state information (CSI)to assist the transmission of the first set of one or more independentdata streams; and cause transmission, in higher layer signaling, of anindication related to aggregation of antenna ports of configured CSI-RSsto be used for CSI reporting.

Example 68 may include the apparatus of example 66 and/or any other oneor more examples disclosed herein, wherein the baseband circuitry is tomap one codeword to one transmission layer when two or more downlinkcontrol information (DCI) messages are to be used to schedule a physicaldownlink shared channel (PDSCH).

Example 69 may include the apparatus of example 66 and/or any other oneor more examples disclosed herein, wherein the baseband circuitry is tomap one codeword to two or more transmission layers associated with oneor more independent data streams of the first set of one or moreindependent data streams or map one codeword to two or more layersassociated with one or more independent data streams of the second setof one or more independent data streams.

Example 70 may include an apparatus to be implemented in an evolved nodeB (eNB) comprising: baseband circuitry to identify control informationrelated to a parameter of a first independent data stream that is to betransmitted by a downlink cell or a second independent data stream thatis to be transmitted by another downlink cell; and cause transmission ofthe first independent data stream and the control information; and radiofrequency (RF) circuitry coupled with the baseband circuitry, the RFcircuitry to transmit the first independent data stream and the controlinformation.

Example 71 may include the apparatus of example 70 and/or any other oneor more examples disclosed herein, wherein antenna ports associated witha CSI reference signal (CSI-RS) are not assumed as quasi co-located, andwherein the baseband circuitry is to use channel state information (CSI)to assist the transmission of the first independent data stream; and theRF circuitry is to transmit, in higher layer signaling, an indicationrelated to aggregation of antenna ports of configured CSI-RSs to be usedfor CSI reporting.

Example 72 may include the apparatus of example 70 and/or any other oneor more examples disclosed herein, wherein the baseband circuitry is tomap one codeword to one transmission layer when two or more downlinkcontrol information (DCI) messages are to be used to schedule a physicaldownlink shared channel (PDSCH).

Example 73 may include the apparatus of example 70 and/or any other oneor more examples disclosed herein, wherein the baseband circuitry is tomap one codeword to two or more layers associated with one or moreindependent data streams including the first independent data stream ormap one codeword to two or more layers associated with one or moreindependent data streams of including the second independent datastream.

Example 74 may include at least one computer-readable medium includinginstructions to cause an evolved node B (eNB), in response to executionof the instructions by the eNB, to: identify control information relatedto a parameter of a first independent data stream that is to betransmitted by a downlink cell or a second independent data stream thatis to be transmitted by another downlink cell; and cause transmission ofthe first independent data stream and the control information. The atleast one computer-readable medium may be a non-transitorycomputer-readable medium.

Example 75 may include the at least one computer-readable medium ofexample 74 and/or any other one or more examples disclosed herein,wherein antenna ports associated with a CSI reference signal (CSI-RS)are not assumed as quasi co-located, and wherein at least one processoris to execute the instructions to: use channel state information (CSI)to assist the transmission of the first independent data stream; andtransmit, in higher layer signaling, an indication related toaggregation of antenna ports of configured CSI-RSs to be used for CSIreporting.

Example 76 may include the at least one computer-readable medium ofexample 74 and/or any other one or more examples disclosed herein,wherein at least one processor is to execute the instructions to: mapone codeword to one transmission layer when two or more downlink controlinformation (DCI) messages are to be used to schedule a physicaldownlink shared channel (PDSCH).

Example 77 may include the at least one computer-readable medium ofexample 74 and/or any other one or more examples disclosed herein,wherein the at least one processor is to execute the instructions to:map one codeword to two or more layers associated with one or moreindependent data streams including the first independent data stream ormap one codeword to two or more layers associated with one or moreindependent data streams of including the second independent datastream.

Example 78 may include a computer-implemented method for providingmulti-cell, multi-point single user (SU) multiple input and multipleoutput (MIMO) transmissions, the method comprising: transmitting, by anevolved node B (eNB), a first set of one or more independent datastreams in a downlink channel from a first transmission point associatedwith the eNB, wherein the first transmission point corresponds to adownlink cell and a second transmission point is one of another eNB or asmallcell base station; generating, by the eNB, control information thatincludes an indication of a parameter of at least one of the first setof one or more independent data streams or a second set of one or moreindependent data streams to be transmitted by the second transmissionpoint in a downlink channel of the second transmission point; andtransmitting, by the eNB, the control information.

Example 79 may include the method of example 78 and/or any other one ormore examples disclosed herein, wherein antenna ports associated with aCSI reference signal (CSI-RS) are not assumed as quasi co-located, andfurther comprising: using, by the eNB, channel state information (CSI)to assist the transmission of the first set of one or more independentdata streams; and transmitting, by the eNB in higher layer signaling, anindication related to aggregation of antenna ports of configured CSI-RSsto be used for CSI reporting.

Example 80 may include the method of example 78 and/or any other one ormore examples disclosed herein, further comprising: mapping, by the eNB,one codeword to one transmission layer when two or more downlink controlinformation (DCI) messages are to be used to schedule a physicaldownlink shared channel (PDSCH).

Example 81 may include the method of example 78 and/or any other one ormore examples disclosed herein, further comprising: mapping, by the eNB,one codeword to two or more transmission layers associated with one ormore independent data streams of the first set of one or moreindependent data streams or mapping one codeword to two or more layersassociated with one or more independent data streams of the second setof one or more independent data streams.

Example 82 may include at least one computer-readable medium includinginstructions to cause an evolved node B (eNB), in response to executionof the instructions by the eNB, to perform the method of any one ofexamples 78-81 and/or any other one or more examples disclosed herein.The at least one computer-readable medium may be a non-transitorycomputer-readable medium.

Example 83 may include the computer-implemented method for providingmulti-cell, multi-point single user (SU) multiple input and multipleoutput (MIMO) transmissions, the method comprising: identifying, by anevolved node B (eNB), control information related to a parameter of afirst independent data stream that is to be transmitted by a downlinkcell or a second independent data stream that is to be transmitted byanother downlink cell; and transmitting, by the eNB, the firstindependent data stream and the control information.

Example 84 may include the method of example 82 and/or any other one ormore examples disclosed herein, wherein antenna ports associated with aCSI reference signal (CSI-RS) are not assumed as quasi co-located, andthe method further comprises: using, by the eNB, channel stateinformation (CSI) to assist the transmission of the first independentdata stream; and transmitting, by the eNB in higher layer signaling, anindication related to aggregation of antenna ports of configured CSI-RSsto be used for CSI reporting.

Example 85 may include the method of example 82 and/or any other one ormore examples disclosed herein, further comprising: mapping, by the eNB,one codeword to one transmission layer when two or more downlink controlinformation (DCI) messages are to be used to schedule a physicaldownlink shared channel (PDSCH).

Example 86 may include the method of example 82 and/or any other one ormore examples disclosed herein, further comprising: mapping, by the eNB,one codeword to two or more layers associated with one or moreindependent data streams including the first independent data stream ormapping one codeword to two or more layers associated with one or moreindependent data streams of including the second independent datastream.

Example 87 may include at least one computer-readable medium includinginstructions to cause an evolved node B (eNB), in response to executionof the instructions by the eNB, to perform the method of any one ofexamples 83-86 and/or any other one or more examples disclosed herein.The at least one computer-readable medium may be a non-transitorycomputer-readable medium.

The foregoing description of the above Examples provides illustrationand description for the example embodiments disclosed herein, but theabove Examples are not intended to be exhaustive or to limit the scopeof the invention to the precise form disclosed. Modifications andvariations are possible in light of the above teachings and/or may beacquired from practice of various implementations of the invention.

1. At least one non-transitory, computer-readable medium includinginstructions that, when executed by one or more processors, cause a userequipment (UE) to: process a first set of one or more independent datastreams received in a downlink channel from a first transmission point;process a second set of one or more independent data streams received ina downlink channel from a second transmission point; process controlinformation received from the first transmission point or the secondtransmission point; determine a quasi co-location assumption to be usedfor estimating channel characteristics for reception of the first set ofone or more independent data streams or for reception of the second setof one or more independent data streams, wherein the quasi co-locationassumption to be used is based on an indication within the controlinformation; and estimate channel characteristics for reception of thefirst set of one or more independent data streams or for reception ofthe second set of one or more independent data streams according to thequasi co-location assumption.
 2. The at least one non-transitory,computer-readable medium of claim 1, wherein at least one independentdata stream of the first set of one or more independent data streamscorresponds to a first layer, and the at least one independent datastream is to be transmitted by at least one antenna port of a pluralityof antenna ports associated with one or more UE-specific referencesignals (RSs) of the first transmission point.
 3. The at least onenon-transitory, computer-readable medium of claim 2, wherein theindication is to indicate that the plurality of antenna ports are notassumed to be quasi co-located with respect to at least one of a Dopplershift, a Doppler spread, an average delay, or a delay spread.
 4. The atleast one non-transitory, computer-readable medium of claim 3, wherein asame Doppler shift, Doppler spread, average delay, and delay spread areassumed over a predefined set of physical resource blocks (PRBs).
 5. Theat least one non-transitory, computer-readable medium of claim 3,wherein the indication is to indicate that antenna ports of theplurality of antenna ports associated with the one or more UE-specificRSs are quasi co-located with one or more antenna ports associated withone or more other RSs.
 6. The at least one non-transitory,computer-readable medium of claim 5, wherein the one or more other RSsinclude one of cell specific RSs (CRSs), channel state informationreference signals (CSI-RSs), or discovery RSs.
 7. The at least onenon-transitory, computer-readable medium of claim 2, wherein theindication is to indicate quasi co-location of antenna ports of theplurality of antenna ports associated with the one or more UE-specificRSs with other RSs, and wherein the instructions, when executed by theone or more processors, cause the UE to: determine the one or more otherRSs using two or more physical downlink shared channel (PDSCH) resourceelement (RE) mapping and Quasi Co-Location Indicator fields.
 8. The atleast one non-transitory, computer-readable medium of claim 2, whereinthe indication is to indicate quasi co-location of antenna ports of theplurality of antenna ports associated with the one or more UE-specificRSs with other RSs, and wherein the instructions, when executed by theone or more processors, cause the UE to: determine the one or more otherRSs using two or more downlink control information (DCI) format 2Dmessages, wherein each of the two or more DCI format 2D messages includeat least one PDSCH RE mapping and Quasi Co-Location Indicator field. 9.The at least one non-transitory, computer-readable medium of claim 2,wherein the indication is to indicate an RE mapping for the one or moreindependent data streams of the first set of one or more independentdata streams and the one or more independent data streams of the secondset of one or more independent data streams, and wherein theinstructions, when executed by the one or more processors, cause the UEto: determine the RE mapping using two or more PDSCH RE Mapping andQuasi-Co-Location Indicator fields.
 10. An apparatus to be implementedin a user equipment (UE) comprising: an antenna array that includes atleast a first receive antenna and a second receive antenna; one or morecomputer-readable storage media having instructions; and one or moreprocessors coupled with the antenna array and the one or morecomputer-readable storage media, wherein at least one processor of theone or more processors is to execute the instructions to: controlreception of a first set of one or more independent data streams in adownlink channel of a first cell using the first receive antennas;control reception of a second set of one or more independent datastreams in a downlink channel of a second cell using the second receiveantennas; control reception of control information from a first downlinkcell using the first receive antennas or a second downlink cell usingthe second receive antennas; determine a quasi co-location assumptionbased on an indication of the control information, wherein the quasico-location assumption to be used for estimating channel characteristicsfor reception of the first set of one or more independent data streamsor for reception of the second set of one or more independent datastreams; and estimate, using the quasi co-location assumption, channelcharacteristics for reception of the first set of one or moreindependent data streams or for reception of the second set of one ormore independent data streams.
 11. The apparatus of claim 10, wherein atleast one independent data stream of the first set of one or moreindependent data streams corresponds to one layer, and the at least oneindependent data stream is transmitted by at least one antenna port of aplurality of antenna ports associated with one or more UE-specificreference signals of the first downlink cell, wherein the plurality ofantenna ports include antenna ports 7-14.
 12. The apparatus of claim 11,wherein the indication is to indicate that the plurality of antennaports are not assumed to be quasi co-located with respect to Dopplershift, Doppler spread, average delay, and/or delay spread, and a sameDoppler shift, Doppler spread, average delay, and delay spread are to beassumed over a predefined set of physical resource blocks (PRBs). 13.The apparatus of claim 12, wherein the antenna ports of the one or moreUE-specific RS antenna ports is quasi co-located with antenna portsassociated with one or more other RSs, wherein the one or more other RSsinclude at least one of cell specific RSs including antenna ports 0-3,channel state information RSs (CSI-RSs) including antenna ports 15-21,or discovery RSs.
 14. The apparatus of claim 11, wherein the controlinformation includes an indication of quasi co-location of the pluralityof antenna ports associated with the one or more UE-specific referencesignals with other reference signals using two or more physical downlinkshared channel (PDSCH) resource element (RE) Mapping andQuasi-Co-Location Indicator fields.
 15. The apparatus of claim 11,wherein the indication is to indicate quasi co-location of the pluralityof antenna ports associated with the one or more UE-specific RSs withother RSs, and the at least one processor of the one or more processorsis to execute the instructions to: determine the other RSs using two ormore downlink control information formats 2D that include one PDSCH REMapping and Quasi-Co-Location Indicator field.
 16. The apparatus ofclaim 11, wherein the indication is to indicate an RE mapping for theone or more independent data streams of the first set of one or moreindependent data streams and the one or more independent data streams ofthe second set of one or more independent data streams, and the at leastone processor of the one or more processors is to execute theinstructions to: determine the RE mapping using two or more PDSCH REMapping and Quasi-Co-Location Indicator fields.
 17. The apparatus ofclaim 10, wherein channel state information (CSI) is used by the firstdownlink cell or the second downlink cell to assist the transmission ofthe first set of one or more independent data streams or the second setof one or more independent data streams and antenna ports associatedwith a CSI reference signal (CSI-RS) are not assumed as quasico-located, and wherein the at least one processor is to execute theinstructions to: control reception, in higher layer signaling, of anindication related to aggregation of the antenna ports of the configuredCSI-RS that should be used for CSI reporting.
 18. At least onenon-transitory, computer-readable medium including instructions to causean evolved node B (eNB), in response to execution of the instructions bythe eNB, to: cause transmission of a first set of one or moreindependent data streams in a downlink channel from a first transmissionpoint associated with the eNB, wherein the first transmission pointcorresponds to a downlink cell and a second transmission point is one ofanother eNB or a smallcell base station; generate control informationthat includes an indication of a parameter of at least one of the firstset of one or more independent data streams or a second set of one ormore independent data streams to be transmitted by the secondtransmission point in a downlink channel of the second transmissionpoint; and cause transmission of the control information.
 19. The atleast one non-transitory, computer-readable medium of claim 18, whereinantenna ports associated with a CSI reference signal (CSI-RS) are notassumed as quasi co-located, and wherein the instructions further causethe eNB, in response to execution of the instructions by the eNB, to:use channel state information (CSI) to assist the transmission of thefirst set of one or more independent data streams; and transmit, inhigher layer signaling, an indication related to aggregation of antennaports of configured CSI-RSs to be used for CSI reporting.
 20. The atleast one non-transitory, computer-readable medium of claim 18, whereinthe instructions further cause the eNB, in response to execution of theinstructions by the eNB, to: map one codeword to one transmission layerwhen two or more downlink control information (DCI) messages are to beused to schedule a physical downlink shared channel (PDSCH); or map onecodeword to two or more transmission layers associated with one or moreindependent data streams of the first set of one or more independentdata streams or map one codeword to two or more layers associated withone or more independent data streams of the second set of one or moreindependent data streams.